Dit is ons nieuw hondje Kira, een kruising van een waterhond en een Podenko. Ze is sinds 7 februari 2024 bij ons en druk bezig ons hart te veroveren. Het is een lief, aanhankelijk hondje, dat zich op een week snel aan ons heeft aangepast. Ze is heel vinnig en nieuwsgierig, een heel ander hondje dan Noleke.
This is our new dog Kira, a cross between a water dog and a Podenko. She has been with us since February 7, 2024 and is busy winning our hearts. She is a sweet, affectionate dog who quickly adapted to us within a week. She is very quick and curious, a very different dog than Noleke.
DEAR VISITOR,
MY BLOG EXISTS ALREADY 12 YEARS AND 11 MONTHS.
ON 06/05/2024 MORE THAN 1.972.210
VISITORS FROM 134 DIFFERENT NATIONS ALREADY FOUND THEIR WAY TO MY BLOG.
THAT IS AN AVERAGE OF 400GUESTS PER DAY.
THANK YOU FOR VISITING MY BLOG AND HOPE YOU ENJOY EACH TIME.
The purpose of this blog is the creation of an open, international, independent and free forum, where every UFO-researcher can publish the results of his/her research. The languagues, used for this blog, are Dutch, English and French.You can find the articles of a collegue by selecting his category. Each author stays resposable for the continue of his articles. As blogmaster I have the right to refuse an addition or an article, when it attacks other collegues or UFO-groupes.
Druk op onderstaande knop om te reageren in mijn forum
Zoeken in blog
Deze blog is opgedragen aan mijn overleden echtgenote Lucienne.
In 2012 verloor ze haar moedige strijd tegen kanker!
In 2011 startte ik deze blog, omdat ik niet mocht stoppen met mijn UFO-onderzoek.
BEDANKT!!!
Een interessant adres?
UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN - DE ALLERLAATSTE NIEUWTJES
UFO's of UAP'S in België en de rest van de wereld In België had je vooral BUFON of het Belgisch UFO-Netwerk, dat zich met UFO's bezighoudt. BEZOEK DUS ZEKER VOOR ALLE OBJECTIEVE INFORMATIE , enkel nog beschikbaar via Facebook en deze blog.
Verder heb je ook het Belgisch-Ufo-meldpunt en Caelestia, die prachtig, doch ZEER kritisch werk leveren, ja soms zelfs héél sceptisch...
Voor Nederland kan je de mooie site www.ufowijzer.nl bezoeken van Paul Harmans. Een mooie site met veel informatie en artikels.
MUFON of het Mutual UFO Network Inc is een Amerikaanse UFO-vereniging met afdelingen in alle USA-staten en diverse landen.
MUFON's mission is the analytical and scientific investigation of the UFO- Phenomenon for the benefit of humanity...
Je kan ook hun site bekijken onder www.mufon.com.
Ze geven een maandelijks tijdschrift uit, namelijk The MUFON UFO-Journal.
Since 02/01/2020 is Pieter ex-president (=voorzitter) of BUFON, but also ex-National Director MUFON / Flanders and the Netherlands. We work together with the French MUFON Reseau MUFON/EUROP.
ER IS EEN NIEUWE GROEPERING DIE ZICH BUFON NOEMT, MAAR DIE HEBBEN NIETS MET ONZE GROEP TE MAKEN. DEZE COLLEGA'S GEBRUIKEN DE NAAM BUFON VOOR HUN SITE... Ik wens hen veel succes met de verdere uitbouw van hun groep. Zij kunnen de naam BUFON wel geregistreerd hebben, maar het rijke verleden van BUFON kunnen ze niet wegnemen...
21-04-2022
The brain-reading devices helping paralysed people to move, talk and touch
The brain-reading devices helping paralysed people to move, talk and touch
Implants are becoming more sophisticated — and are attracting commercial interest.
A person with paralysis controls a prosthetic arm using their brain activity.
Credit: Pitt/UPMC
James Johnson hopes to drive a car again one day. If he does, he will do it using only his thoughts.
In March 2017, Johnson broke his neck in a go-carting accident, leaving him almost completely paralysed below the shoulders. He understood his new reality better than most. For decades, he had been a carer for people with paralysis. “There was a deep depression,” he says. “I thought that when this happened to me there was nothing — nothing that I could do or give.”
But then Johnson’s rehabilitation team introduced him to researchers from the nearby California Institute of Technology (Caltech) in Pasadena, who invited him to join a clinical trial of a brain–computer interface (BCI). This would first entail neurosurgery to implant two grids of electrodes into his cortex. These electrodes would record neurons in his brain as they fire, and the researchers would use algorithms to decode his thoughts and intentions. The system would then use Johnson’s brain activity to operate computer applications or to move a prosthetic device. All told, it would take years and require hundreds of intensive training sessions. “I really didn’t hesitate,” says Johnson.
The first time he used his BCI, implanted in November 2018, Johnson moved a cursor around a computer screen. “It felt like The Matrix,” he says. “We hooked up to the computer, and lo and behold I was able to move the cursor just by thinking.”
Johnson has since used the BCI to control a robotic arm, use Photoshop software, play ‘shoot-’em-up’ video games, and now to drive a simulated car through a virtual environment, changing speed, steering and reacting to hazards. “I am always stunned at what we are able to do,” he says, “and it’s frigging awesome.”
Johnson is one of an estimated 35 people who have had a BCI implanted long-term in their brain. Only around a dozen laboratories conduct such research, but that number is growing. And in the past five years, the range of skills these devices can restore has expanded enormously. Last year alone, scientists described a study participant using a robotic arm that could send sensory feedback directly to his brain1; a prosthetic speech device for someone left unable to speak by a stroke2; and a person able to communicate at record speeds by imagining himself handwriting3.
James Johnson uses his neural interface to create art by blending images.
Credit: Tyson Aflalo
So far, the vast majority of implants for recording long-term from individual neurons have been made by a single company: Blackrock Neurotech, a medical-device developer based in Salt Lake City, Utah. But in the past seven years, commercial interest in BCIs has surged. Most notably, in 2016, entrepreneur Elon Musk launched Neuralink in San Francisco, California, with the goal of connecting humans and computers. The company has raised US$363 million. Last year, Blackrock Neurotech and several other newer BCI companies also attracted major financial backing.
Bringing a BCI to market will, however, entail transforming a bespoke technology, road-tested in only a small number of people, into a product that can be manufactured, implanted and used at scale. Large trials will need to show that BCIs can work in non-research settings and demonstrably improve the everyday lives of users — at prices that the market can support. The timeline for achieving all this is uncertain, but the field is bullish. “For thousands of years, we have been looking for some way to heal people who have paralysis,” says Matt Angle, founding chief executive of Paradromics, a neurotechnology company in Austin, Texas. “Now we’re actually on the cusp of having technologies that we can leverage for those things.”
Interface evolution
In June 2004, researchers pressed a grid of electrodes into the motor cortex of a man who had been paralysed by a stabbing. He was the first person to receive a long-term BCI implant. Like most people who have received BCIs since, his cognition was intact. He could imagine moving, but he had lost the neural pathways between his motor cortex and his muscles. After decades of work in many labs in monkeys, researchers had learnt to decode the animals’ movements from real-time recordings of activity in the motor cortex. They now hoped to infer a person’s imagined movements from brain activity in the same region.
In 2006, a landmark paper4 described how the man had learnt to move a cursor around a computer screen, control a television and use robotic arms and hands just by thinking. The study was co-led by Leigh Hochberg, a neuroscientist and critical-care neurologist at Brown University in Providence, Rhode Island, and at Massachusetts General Hospital in Boston. It was the first of a multicentre suite of trials called BrainGate, which continues today.
“It was a very simple, rudimentary demonstration,” Hochberg says. “The movements were slow or imprecise — or both. But it demonstrated that it might be possible to record from the cortex of somebody who was unable to move and to allow that person to control an external device.”
Today’s BCI users have much finer control and access to a wider range of skills. In part, this is because researchers began to implant multiple BCIs in different brain areas of the user and devised new ways to identify useful signals. But Hochberg says the biggest boost has come from machine learning, which has improved the ability to decode neural activity. Rather than trying to understand what activity patterns mean, machine learning simply identifies and links patterns to a user’s intention.
“We have neural information; we know what that person who is generating the neural data is attempting to do; and we’re asking the algorithms to create a map between the two,” says Hochberg. “That turns out to be a remarkably powerful technique.”
Motor independence
Asked what they want from assistive neurotechnology, people with paralysis most often answer “independence”. For people who are unable to move their limbs, this typically means restoring movement.
One approach is to implant electrodes that directly stimulate the muscles of a person’s own limbs and have the BCI directly control these. “If you can capture the native cortical signals related to controlling hand movements, you can essentially bypass the spinal-cord injury to go directly from brain to periphery,” says Bolu Ajiboye, a neuroscientist at Case Western Reserve University in Cleveland, Ohio.
In 2017, Ajiboye and his colleagues described a participant who used this system to perform complex arm movements, including drinking a cup of coffee and feeding himself5. “When he first started the study,” Ajiboye says, “he had to think very hard about his arm moving from point A to point B. But as he gained more training, he could just think about moving his arm and it would move.” The participant also regained a sense of ownership of the arm.
Ajiboye is now expanding the repertoire of command signals his system can decode, such as those for grip force. He also wants to give BCI users a sense of touch, a goal being pursued by several labs.
In 2015, a team led by neuroscientist Robert Gaunt at the University of Pittsburgh in Pennsylvania, reported implanting an electrode array in the hand region of a person’s somatosensory cortex, where touch information is processed6. When they used the electrodes to stimulate neurons, the person felt something akin to being touched.
Gaunt then joined forces with Pittsburgh colleague Jennifer Collinger, a neuroscientist advancing the control of robotic arms by BCIs. Together, they fashioned a robotic arm with pressure sensors embedded in its fingertips, which fed into electrodes implanted in the somatosensory cortex to evoke a synthetic sense of touch1. It was not an entirely natural feeling — sometimes it felt like pressure or being prodded, other times it was more like a buzzing, Gaunt explains. Nevertheless, tactile feedback made the prosthetic feel much more natural to use, and the time it took to pick up an object was halved, from roughly 20 seconds to 10.
Implanting arrays into brain regions that have different roles can add nuance to movement in other ways. Neuroscientist Richard Andersen — who is leading the trial at Caltech in which Johnson is participating — is trying to decode users’ more-abstract goals by tapping into the posterior parietal cortex (PPC), which forms the intention or plan to move7. That is, it might encode the thought ‘I want a drink’, whereas the motor cortex directs the hand to the coffee, then brings the coffee to the mouth.
Andersen’s group is exploring how this dual input aids BCI performance, contrasting use of the two cortical regions alone or together. Unpublished results show that Johnson’s intentions can be decoded more quickly in the PPC, “consistent with encoding the goal of the movement”, says Tyson Aflalo, a senior researcher in Andersen’s laboratory. Motor-cortex activity, by contrast, lasts throughout the whole movement, he says, “making the trajectory less jittery”.
This new type of neural input is helping Johnson and others to expand what they can do. Johnson uses the driving simulator, and another participant can play a virtual piano using her BCI.
Movement into meaning
“One of the most devastating outcomes related to brain injuries is the loss of ability to communicate,” says Edward Chang, a neurosurgeon and neuroscientist at the University of California, San Francisco. In early BCI work, participants could move a cursor around a computer screen by imagining their hand moving, and then imagining grasping to ‘click’ letters — offering a way to achieve communication. But more recently, Chang and others have made rapid progress by targeting movements that people naturally use to express themselves.
The benchmark for communication by cursor control — roughly 40 characters per minute8 — was set in 2017 by a team led by Krishna Shenoy, a neuroscientist at Stanford University in California.
Then, last year, this group reported3 an approach that enabled study participant Dennis Degray, who can speak but is paralysed from the neck down, to double the pace.
Shenoy’s colleague Frank Willett suggested to Degray that he imagine handwriting while they recorded from his motor cortex (see ‘Turning thoughts into type’). The system sometimes struggled to parse signals relating to letters that are handwritten in a similar way, such as r, n and h, but generally it could easily distinguish the letters. The decoding algorithms were 95% accurate at baseline, but when autocorrected using statistical language models that are similar to predictive text in smartphones, this jumped to 99%.
“You can decode really rapid, very fine movements,” says Shenoy, “and you’re able to do that at 90 characters per minute.”
Degray has had a functional BCI in his brain for nearly 6 years, and is a veteran of 18 studies by Shenoy’s group. He says it’s remarkable how effortless tasks become. He likens the process to learning to swim, saying, “You thrash around a lot at first, but all of a sudden, everything becomes understandable.”
Chang’s approach to restoring communication focuses on speaking rather than writing, albeit using a similar principle. Just as writing is formed of distinct letters, speech is formed of discrete units called phonemes, or individual sounds. There are around 50 phonemes in English, and each is created by a stereotyped movement of the vocal tract, tongue and lips.
Chang’s group first worked on characterizing the part of the brain that generates phonemes and, thereby, speech — an ill-defined region called the dorsal laryngeal cortex. Then, the researchers applied these insights to create a speech-decoding system that displayed the user’s intended speech as text on a screen. Last year, they reported2 that this device enabled a person left unable to talk by a brainstem stroke to communicate, using a preselected vocabulary of 50 words and at a rate of 15 words per minute. “The most important thing that we’ve learnt,” Chang says, “is that it’s no longer a theoretical; it’s truly possible to decode full words.”
Neuroscientist Edward Chang (right) at the University of California, San Francisco, helps a man with paralysis to speak through a brain implant that connects to a computer.
Credit: Mike Kai Chen/The New York Times/Redux/eyevine
Unlike other high-profile BCI breakthroughs, Chang didn’t record from single neurons. Instead, he used electrodes placed on the cortical surface that detect the averaged activity of neuronal populations. The signals are not as fine-grained as those from electrodes implanted in the cortex, but the approach is less invasive.
The most profound loss of communication occurs in people in a completely locked-in state, who remain conscious but are unable to speak or move. In March, a team including neuroscientist Ujwal Chaudhary and others at the University of Tübingen, Germany, reported9 restarting communication with a man who has amyotrophic lateral sclerosis (ALS, or motor neuron disease). The man had previously relied on eye movements to communicate, but he gradually lost the ability to move his eyes.
The team of researchers gained consent from the man’s family to implant a BCI and tried asking him to imagine movements to use his brain activity to choose letters on a screen. When this failed, they tried playing a sound that mimicked the man’s brain activity — a higher tone for more activity, lower for less — and taught him to modulate his neural activity to heighten the pitch of a tone to signal ‘yes’ and to lower it for ‘no’. That arrangement allowed him to pick out a letter every minute or so.
The method differs from that in a paper10 published in 2017, in which Chaudhary and others used a non-invasive technique to read brain activity. Questions were raised about the work and the paper was retracted, but Chaudhary stands by it.
These case studies suggest that the field is maturing rapidly, says Amy Orsborn, who researches BCIs in non-human primates at the University of Washington in Seattle. “There’s been a noticeable uptick in both the number of clinical studies and of the leaps that they’re making in the clinical space,” she says. “What comes along with that is the industrial interest”.
Lab to market
Although such achievements have attracted a flurry of attention from the media and investors, the field remains a long way from improving day-to-day life for people who’ve lost the ability to move or speak. Currently, study participants operate BCIs in brief, intensive sessions; nearly all must be physically wired to a bank of computers and supervised by a team of scientists working constantly to hone and recalibrate the decoders and associated software. “What I want,” says Hochberg, speaking as a critical-care neurologist, “is a device that is available, that can be prescribed, that is ‘off the shelf’ and can be used quickly.” In addition, such devices would ideally last users a lifetime.
Many leading academics are now collaborating with companies to develop marketable devices. Chaudhary, by contrast, has co-founded a not-for-profit company, ALS Voice, in Tübingen, to develop neurotechnologies for people in a completely locked-in state.
Blackrock Neurotech’s existing devices have been a mainstay of clinical research for 18 years, and it wants to market a BCI system within a year, according to chairman Florian Solzbacher. The company came a step closer last November, when the US Food and Drug Administration (FDA), which regulates medical devices, put the company’s products onto a fast-track review process to facilitate developing them commercially.
This possible first product would use four implanted arrays and connect through wires to a miniaturized device, which Solzbacher hopes will show how people’s lives can be improved. “We’re not talking about a 5, 10 or 30% improvement in efficacy,” he says. “People can do something they just couldn’t before.”
Blackrock Neurotech is also developing a fully implantable wireless BCI intended to be easier to use and to remove the need to have a port in the user’s cranium. Neuralink and Paradromics have aimed to have these features from the outset in the devices they are developing.
These two companies are also aiming to boost signal bandwidth, which should improve device performance, by increasing the number of recorded neurons. Paradromics’s interface — currently being tested in sheep — has 1,600 channels, divided between 4 modules.
Neuralink’s system uses very fine, flexible electrodes, called threads, that are designed to both bend with the brain and to reduce immune reactions, says Shenoy, who is a consultant and adviser to the company. The aim is to make the device more durable and recordings more stable. Neuralink has not published any peer-reviewed papers, but a 2021 blogpost reported the successful implantation of threads in a monkey’s brain to record at 1,024 sites (see go.nature.com/3jt71yq). Academics would like to see the technology published for full scrutiny, and Neuralink has so far trialled its system only in animals. But, Ajiboye says, “if what they’re claiming is true, it’s a game-changer”.
Just one other company besides Blackrock Neurotech has implanted a BCI long-term in humans — and it might prove an easier sell than other arrays. Synchron in New York City has developed a ‘stentrode’ — a set of 16 electrodes fashioned around a blood-vessel stent11. Fitted in a day in an outpatient setting, this device is threaded through the jugular vein to a vein on top of the motor cortex. First implanted in a person with ALS in August 2019, the technology was put on a fast-track review path by the FDA a year later.
The ‘stentrode’ interface can translate brain signals from the inside of a blood vessel without the need for open-brain surgery.
Credit: Synchron, Inc.
Akin to the electrodes Chang uses, the stentrode lacks the resolution of other implants, so can’t be used to control complex prosthetics. But it allows people who cannot move or speak to control a cursor on a computer tablet, and so to text, surf the Internet and control connected technologies.
Synchron’s co-founder, neurologist Thomas Oxley, says the company is now submitting the results of a four-person feasibility trial for publication, in which participants used the wireless device at home whenever they chose. “There’s nothing sticking out of the body. And it’s always working,” says Oxley. The next step before applying for FDA approval, he says, is a larger-scale trial to assess whether the device meaningfully improves functionality and quality of life.
Challenges ahead
Most researchers working on BCIs are realistic about the challenges before them. “If you take a step back, it is really more complicated than any other neurological device ever built,” says Shenoy. “There’s probably going to be some hard growing years to mature the technology even more.”
Orsborn stresses that commercial devices will have to work without expert oversight for months or years — and that they need to function equally well in every user. She anticipates that advances in machine learning will address the first issue by providing recalibration steps for users to implement. But achieving consistent performance across users might present a greater challenge.
“Variability from person to person is the one where I don’t think we know what the scope of the problem is,” Orsborn says. In non-human primates, even small variations in electrode positioning can affect which circuits are tapped. She suspects there are also important idiosyncrasies in exactly how different individuals think and learn — and the ways in which users’ brains have been affected by their various conditions.
Finally, there is widespread acknowledgement that ethical oversight must keep pace with this rapidly evolving technology. BCIs present multiple concerns, from privacy to personal autonomy. Ethicists stress that users must retain full control of the devices’ outputs. And although current technologies cannot decode people’s private thoughts, developers will have records of users’ every communication, and crucial data about their brain health. Moreover, BCIs present a new type of cybersecurity risk.
There is also a risk to participants that their devices might not be supported forever, or that the companies that manufacture them fold. There are already instances in which users were let down when their implanted devices were left unsupported.
Degray, however, is eager to see BCIs reach more people. What he would like most from assistive technology is to be able to scratch his eyebrow, he says. “Everybody looks at me in the chair and they always say, ‘Oh, that poor guy, he can’t play golf any more.’ That’s bad. But the real terror is in the middle of the night when a spider walks across your face. That’s the bad stuff.”
For Johnson, it’s about human connection and tactile feedback; a hug from a loved one. “If we can map the neurons that are responsible for that and somehow filter it into a prosthetic device some day in the future, then I will feel well satisfied with my efforts in these studies.”
While working on his doctorate in theoretical physics in the early 1970s, Saul Teukolsky solved a problem that seemed purely hypothetical. Imagine a black hole, the ghostly knot of gravity that forms when, say, a massive star burns out and collapses to an infinitesimal point. Suppose you perturb it, as you might strike a bell. How does the black hole respond?
Teukolsky, then a graduate student at the California Institute of Technology (Caltech), attacked the problem with pencil, paper, and Albert Einstein's theory of gravity, general relativity. Like a bell, the black hole would oscillate at one main frequency and multiple overtones, he found. The oscillations would quickly fade as the black hole radiated gravitational waves—ripples in the fabric of space itself. It was a sweet problem, says Teukolsky, now at Cornell University. And it was completely abstract—until 5 years ago.
In February 2016, experimenters with the Laser Interferometer Gravitational-Wave Observatory (LIGO), a pair of huge instruments in Louisiana and Washington, reported the first observation of fleeting gravitational ripples, which had emanated from two black holes, each about 30 times as massive as the Sun, spiraling into each other 1.3 billion light-years away. LIGO even sensed the "ring down": the shudder of the bigger black hole produced by the merger. Teukolsky's old thesis was suddenly cutting-edge physics.
"The thought that anything I did would ever have implications for anything measurable in my lifetime was so far-fetched that the last 5 years have seemed like living in a dream world," Teukolsky says. "I have to pinch myself, it doesn't feel real."
Fantastical though it may seem, scientists can now study black holes as real objects. Gravitational wave detectors have spotted four dozen black hole mergers since LIGO's breakthrough detection. In April 2019, an international collaboration called the Event Horizon Telescope (EHT) produced the first image of a black hole. By training radio telescopes around the globe on the supermassive black hole in the heart of the nearby galaxy Messier 87 (M87), EHT imaged a fiery ring of hot gas surrounding the black hole's inky "shadow." Meanwhile, astronomers are tracking stars that zip close to the black hole in the center of our own Galaxy, following paths that may hold clues to the nature of the black hole itself.
The observations are already challenging astrophysicists' assumptions about how black holes form and influence their surroundings. The smaller black holes detected by LIGO and, now, the European gravitational wave detector Virgo in Italy have proved heavier and more varied than expected, straining astrophysicists' understanding of the massive stars from which they presumably form. And the environment around the supermassive black hole in our Galaxy appears surprisingly fertile, teeming with young stars not expected to form in such a maelstrom. But some scientists feel the pull of a more fundamental question: Are they really seeing the black holes predicted by Einstein's theory?
Some theorists say the answer is most likely a ho-hum yes. "I don't think we're going to learn anything more about general relativity or the theory of black holes from any of this," says Robert Wald, a gravitational theorist at the University of Chicago. Others aren't so sure. "Are black holes strictly the same as you would expect with general relativity or are they different?" asks Clifford Will, a gravitational theorist at the University of Florida. "That's going to be a major thrust of future observations." Any anomalies would require a rethink of Einstein's theory, which physicists suspect is not the final word on gravity, as it doesn't jibe with the other cornerstone of modern physics, quantum mechanics.
Even though it's very unlikely, it would be so amazingly important if we found that there was any deviation [from general relativity].
SEAN CARROLL
CALIFORNIA INSTITUTE OF TECHNOLOGY
Using multiple techniques, researchers are already gaining different, complementary views of these strange objects, says Andrea Ghez, an astrophysicist at the University of California, Los Angeles, who shared the 2020 Nobel Prize in Physics for inferring the existence of the supermassive black hole in the heart of our Galaxy. "We're still a long way from putting a complete picture together," she says, "but we're certainly getting more of the puzzle pieces in place."
CONSISTING OF PURE gravitational energy, a black hole is a ball of contradictions. It contains no matter, but, like a bowling ball, possesses mass and can spin. It has no surface, but has a size. It behaves like an imposing, weighty object, but is really just a peculiar region of space.
Or so says general relativity, which Einstein published in 1915. Two centuries earlier, Isaac Newton had posited that gravity is a force that somehow reaches through space to attract massive objects to one another. Einstein went deeper and argued that gravity arises because massive things such as stars and planets warp space and time—more accurately, spacetime—causing the trajectories of freely falling objects to curve into, say, the parabolic arc of a thrown ball.
Early predictions of general relativity differed only slightly from those of Newton's theory. Whereas Newton predicted that a planet should orbit its star in an ellipse, general relativity predicts that the orientation of the ellipse should advance slightly, or precess, with each orbit. In the first triumph of the theory, Einstein showed it accounted for the previously unexplained precession of the orbit of the planet Mercury. Only years later did physicists realize the theory also implied something far more radical.
In 1939, theorist J. Robert Oppenheimer and colleagues calculated that when a sufficiently massive star burned out, no known force could stop its core from collapsing to an infinitesimal point, leaving behind its gravitational field as a permanent pit in spacetime. Within a certain distance of the point, gravity would be so strong that not even light could escape. Anything closer would be cut off from the rest of the universe, David Finkelstein, a theorist at Caltech, argued in 1958. This "event horizon" isn't a physical surface. An astronaut falling past it would notice nothing special. Nevertheless, reasoned Finkelstein, who died just days before LIGO's announcement in 2016, the horizon would act like a one-way membrane, letting things fall in, but preventing anything from getting out.
According to general relativity, these objects—eventually named black holes by famed theorist John Archibald Wheeler—should also exhibit a shocking sameness. In 1963, Roy Kerr, a mathematician from New Zealand, worked out how a spinning black hole of a given mass would warp and twist spacetime. Others soon proved that, in general relativity, mass and spin are the only characteristics a black hole can have, implying that Kerr's mathematical formula, known as the Kerr metric, describes every black hole there is. Wheeler dubbed the result the no-hair theorem to emphasize that two black holes of the same mass and spin are as indistinguishable as bald pates. Wheeler himself was bald, Teukolsky notes, "so maybe it was bald pride."
Some physicists suspected black holes might not exist outside theorists' imaginations, says Sean Carroll, a theorist at Caltech. Skeptics argued that black holes might be an artifact of general relativity's subtle math, or that they might only form under unrealistic conditions, such as the collapse of a perfectly spherical star. However, in the late 1960s, Roger Penrose, a theorist at the University of Oxford, dispelled such doubts with rigorous math, for which he shared the 2020 Nobel Prize in Physics. "Penrose exactly proved that, no, no, even if you have a lumpy thing, as long as the density became high enough, it was going to collapse to a black hole," Carroll says.
Soon enough, astronomers began to see signs of actual black holes. They spotted tiny x-ray sources, such as Cygnus X-1, each in orbit around a star. Astrophysicists deduced that the x-rays came from gas flowing from the star and heating up as it fell onto the mysterious object. The temperature of the gas and the details of the orbit implied the x-ray source was too massive and too small to be anything but a black hole. Similar reasoning suggested quasars, distant galaxies spewing radiation, are powered by supermassive black holes in their centers.
But no one could be sure those black holes actually are what theorists had pictured, notes Feryal Özel, an astrophysicist at the University of Arizona (UA). For example, "Very little that we have done so far establishes the presence of an event horizon," she says. "That is an open question."
Now, with multiple ways to peer at black holes, scientists can start to test their understanding and look for surprises that could revolutionize physics. "Even though it's very unlikely, it would be so amazingly important if we found that there was any deviation" from the predictions of general relativity, Carroll says. "It's a very high-risk, high-reward question."
SCIENTISTS HOPE TO ANSWER three specific questions: Do the observed black holes really have event horizons? Are they as featureless as the no-hair theorem says? And do they distort spacetime exactly as the Kerr metric predicts?
Perhaps the simplest tool for answering them is one that Ghez developed. Since 1995, she and colleagues have used the 10-meter Keck telescope in Hawaii to track stars around a radio source known as Sagittarius A* (Sgr A*) in the center of our Galaxy. In 1998, the stars' high speeds revealed they orbit an object 4 million times as massive as the Sun. Because Sgr A* packs so much mass into such a small volume, general relativity predicts it must be a supermassive black hole. Reinhard Genzel, an astrophysicist at the Max Planck Institute for Extraterrestrial Physics, independently tracked the stars to reach the same conclusion and shared the Nobel Prize with Ghez.
C. BICKEL/SCIENCE
Much of the information comes from a single star, dubbed SO2 by Ghez, which whips around Sgr A* once every 16 years. Just as the orbit of Mercury around the Sun precesses, so, too, should the orbit of SO2. Ghez and colleagues are now trying to tease out that precession from the extremely complicated data. "We're right on the cusp," she says. "We have a signal, but we're still trying to convince ourselves that it's real." (In April 2020, Genzel and colleagues claimed to have seen the precession.)
If they get a little lucky, Ghez and company hope to look for other anomalies that would probe the nature of the supermassive black hole. Close to the black hole, its spin should modify the precession of a star's orbit in a way that's predictable from Kerr's mathematical description. "If there were stars even closer than the ones they've seen—maybe 10 times closer—then you could test whether the Kerr metric is exactly correct," Will says.
The star tracking will likely never probe very close to the event horizon of Sgr A*, which could fit within the orbit of Mercury. But EHT, which combines data from 11 radio telescopes or arrays around the world to form, essentially, one big telescope, has offered a closer look at a different supermassive black hole, the 6.5-billion-solar-mass beast in M87.
The famous image the team released 2 years ago, which resembles a fiery circus hoop, is more complicated than it looks. The bright ring emanates from hot gas, but the dark center is not the black hole itself. Rather it is a "shadow" cast by the black hole as its gravity distorts or "lenses" the light from the gas in front of it. The edge of shadow marks not the event horizon, but rather a distance about 50% farther out where spacetime is distorted just enough so that passing light circles the black hole, neither escaping nor falling into the maw.
Gravity from a supermassive black hole casts a dark circular “shadow” in the glow from surrounding gas in the iconic image captured by the Event Horizon Telescope collaboration.EVENT HORIZON TELESCOPE COLLABORATION ET AL.
Even so, the image holds clues about the object at its center. The spectrum of the glowing ring could reveal, for example, whether the object has a physical surface rather than an event horizon. Matter crashing onto a surface would shine even brighter than stuff sliding into a black hole, Özel explains. (So far researchers have seen no spectral distortion.) The shadow's shape can also test the classical picture of a black hole. A spinning black hole's event horizon should bulge at the equator. However, other effects in general relativity should counteract that effect on the shadow. "Because of a very funky cancellation of squishing in different directions, the shadow still looks circular," Özel says. "That's why the shape of the shadow becomes a direct test of the no-hair theorem."
Some researchers doubt EHT can image the black hole with enough precision for such tests. Samuel Gralla, a theorist at UA, questions whether EHT is even seeing a black hole shadow or merely viewing the disk of gas swirling around the black hole from the top down, in which case the dark spot is simply the eye of that astrophysical hurricane. But Özel says that even with limited resolution, EHT can contribute significantly to testing general relativity in the conceptual terra incognita around a black hole.
Gravitational waves, in contrast, convey information straight from the black holes themselves. Churned out when black holes spiral together at half the speed of light, these ripples in spacetime pass unimpeded through ordinary matter. LIGO and Virgo have now detected mergers of black holes with masses ranging from three to 86 solar masses.
The mergers can probe the black holes in several ways, says Frank Ohme, a gravitational theorist and LIGO member at the Max Planck Institute for Gravitational Physics. Assuming the objects are classical black holes, researchers can calculate from general relativity how the chirplike gravitational wave signal from a merger should speed up, climax in a spike, and then ring down. If the massive partners are actually larger material objects, then as they draw close they should distort each other, altering the peak of the signal. So far, researchers see no alterations, Ohme says.
The merger produces a perturbed black hole just like the one in Teukolsky's old thesis, offering another test of general relativity. The final black hole undulates briefly but powerfully, at one main frequency and multiple shorter lived overtones. According to the no-hair theorem, those frequencies and lifetimes only depend on the final black hole's mass and spin. "If you analyze each mode individually, they all have to point to the same black hole mass and spin or something's wrong," Ohme says.
In September 2019, Teukolsky and colleagues teased out the main vibration and a single overtone from a particularly loud merger. If experimenters can improve the sensitivity of their detectors, Ohme says, they might be able to spot two or three overtones—enough to start to test the no-hair theorem.
FUTURE INSTRUMENTS MAY make such tests much easier. The 30-meter optical telescopes being built in Chile and Hawaii should scrutinize the neighborhood of Sgr A* with a resolution roughly 80 times better than current instruments, Ghez says, possibly spying closer stars. Similarly, EHT researchers are adding more radio dishes to their network, which should enable them to image the black hole in M87 more precisely. They're also trying to image Sgr A*.
Meanwhile, gravitational wave researchers are already planning the next generation of more sensitive detectors, including the Laser Interferometer Space Antenna (LISA), made up of three satellites flying in formation millions of kilometers apart. To be launched in the 2030s, LISA would be so sensitive that it could spot an ordinary stellar-mass black hole spiraling into a much bigger supermassive black hole in a distant galaxy, says Nicolas Yunes, a theoretical physicist at the University of Illinois, Urbana-Champaign.
The smaller black hole would serve as a precise probe of the spacetime around the bigger black hole, revealing whether it warps and twists exactly as the Kerr metric dictates. An affirmative result would cement the case that black holes are what general relativity predicts, Yunes says. "But you have to wait for LISA."
In the meantime, the sudden observability of black holes has changed the lives of gravitational physicists. Once the domain of thought experiments and elegant but abstract calculations like Teukolsky's, general relativity and black holes are suddenly the hottest things in fundamental physics, with experts in general relativity feeding vital input to billion-dollar experiments. "I felt this transition very literally myself," Ohme says. "It was really a small niche community, and with the detection of gravitational waves that all changed."
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Alternatives to black holes are scarce and strange
At one time, many physicists resisted the notion of a black hole, a ghostly, self-sustaining gravitational field so intense that not even light can escape. Now, theorists have few alternatives to these creepy holes in the universe.
Any alternative to a black hole must be some dark, dense material orb that’s slightly bigger than a black hole of the same mass. (Were the thing smaller, its own gravity would create a black hole around it.) Observers might detect the orb’s surface by spotting matter crashing onto it and heating up. Or they might deduce the greater size of the object as it swirls around a companion and tears into it before merging.
One hypothetical possibility is a gravastar: a thin material shell filled with dark energy, the mysterious space-stretching stuff that appears to be accelerating the expansion of the universe. A gravastar would have a solid surface rather than an event horizon, the point of no return that is the defining feature of a black hole. It satisfies the mathematical requirements of Albert Einstein’s theory of gravity, general relativity, says Carlos Palenzuela Luque, a gravitational theorist at the University of the Balearic Islands. However, nobody knows how a gravastar could ever form, he says.
Easier to produce might be a boson star, which would consist of exotic, massive Higgs bosons or nearly massless hypothetical particles called axions. Higgs bosons or axions could crowd into a single quantum wave, yielding a density approaching that of a black hole. However, Palenzuela Luque notes, boson stars would likely have masses in a narrow range, whereas a black hole can have any mass. Observed masses vary by factors of billions.
Black hole alternatives “is an area that’s maybe undertheorized,”says Sean Carroll, a theorist at the California Institute of Technology. But that would surely change if observations showed the current description of black holes isn’t quite right. “When we have something to guide our search, we will be able to say something new,” Palenzuela Luque says. “Right now, everything is so speculative.”
Uranus has been sadly neglected. Probes have visited Mars, Venus, Saturn, Jupiter, and Mercury. Heck, even Jupiter's moons are getting their own spacecraft. But the ice giants Uranus and Neptune, in the distant reaches of our Solar System, have not had a single dedicated visitor.
In a new report laying out the top priorities for planetary science and astrobiology, a panel of experts from the US National Academies advises that this omission be rectified. For initiation within the next decade, the committee put a Uranus probe at top priority as the next planetary flagship mission.
"The committee prioritizes the Uranus Orbiter and Probe (UOP) as the highest-priority new Flagship mission for initiation in the decade 2023–2032," the committee wrote in its report.
This probe, the report elaborated, would perform a multi-year orbital tour of Uranus, probing its stinky atmosphere. The mission would provide an unprecedented wealth of information on ice giants in general, and Uranus and its moons in particular – one of the most intriguing and mysterious major objects in the Solar System.
All this, the committee noted, suggests that Uranus warrants significant investigation, not just for its own sake, but for better understanding the evolutionary history of the entire Solar System – especially since the last probe to come close to the planet was Voyager 2 on a flyby in 1986.
The panel has identified several launch windows in the 2030s, with the earliest being 2031; planetary probes are a long game.
"Uranus is one of the most intriguing bodies in the Solar System," the scientists wrote. "Its low internal energy, active atmospheric dynamics, and complex magnetic field all present major puzzles.
"A primordial giant impact may have produced the planet's extreme axial tilt and possibly its rings and satellites, although this is uncertain. Uranus's large ice-rock moons displayed surprising evidence of geological activity in limited Voyager 2 flyby data, and are potential ocean worlds."
Ocean worlds are of great interest to astrobiologists. Scientists believe that on the ocean floors of these geologically active bodies, volcanic vents may allow entire ecosystems based on a chemosynthetic food web to thrive, much like hydrothermal vents here on Earth.
These bodies, of which several have been identified in the Solar System, are the most promising candidates for finding extraterrestrial life.
On that note, the committee identified ocean world Enceladus, a moon of Saturn, as its second-most top priority, with a mission named the Enceladus Orbilander. This ice-covered body has been observed venting plumes of vapor into space from its internal ocean. Sampling these plumes could assess the habitability of Enceladus' ocean, and perhaps even detect signs of life deep within.
A recommendation in the decadal report is a weighty one indeed, but that's no guarantee that a mission will be initiated. The previous report, Vision and Voyages for Planetary Science in the Decade 2013-2022, also recommended a Uranus mission, as well as an Enceladus mission, albeit at a lower priority.
The cost of a mission to Uranus could be over US$4 billion, but the potential scientific gain would be priceless. So, too, could be the gain from an in-depth exploration of Enceladus.
The two highest-priority missions in the previous survey were a Mars sample return mission, and a mission to Europa, an ice moon with a suspected internal ocean orbiting Jupiter. Both of those missions made the cut, and are currently in development. This bodes well for our future exploration of the outer Solar System.
Other recommendations in the new report included continuation of the Mars sample return mission; restoration of the Mars exploration program; continued support for lunar exploration; and, for the first time, improvement of NASA's program to find and track asteroids that pose a threat to life on Earth.
It may be a long road ahead to reach any or all of these goals. But the journey to the stars begins with small steps.
"This report sets out an ambitious but practicable vision for advancing the frontiers of planetary science, astrobiology, and planetary defense in the next decade," said astrophysicist Robin Canup of the Planetary Sciences Directorate at the Southwest Research Institute, and co-chair of the National Academies' steering committee for the decadal survey.
"This recommended portfolio of missions, high-priority research activities, and technology development will produce transformative advances in human knowledge and understanding about the origin and evolution of the Solar System, and of life and the habitability of other bodies beyond Earth."
The uncanny resemblance between features on Europa's frozen surface and a landform in Greenland suggest the icy-moon may be capable of harboring life.
Europa is the fourth largest moon of Jupiter and is thought to have a substantial liquid water ocean under its 15 mile thick crust of ice.
A team from Stanford University explored similarities between double ridges on the surface of Europa, and smaller versions of the features found under Greenland's ice.
Ice-penetrating radar data revealed that refreezing of liquid subsurface water drove the formation of Greenland's double ridge, and if Europa's formed the same way, it could signal the presence of large amounts of liquid water near the surface.
If Europa's features form the same way, this could signal the presence of copious amounts of liquid water - a key ingredient for life - near the surface of the thick outer ice shell of Jupiter's fourth largest moon.
The uncanny resemblance between features on Europa's frozen surface and a landform in Greenland suggest the icy-moon may be capable of harboring life
The study explored similarities between the elongated landforms, called double ridges, that are linear, with two peaks and a central trough between them, and slicing through one looks like a capital letter 'M'.
'If you sliced through one and looked at the cross section, it would look a bit like the capital letter M,' said Stanford University geophysicist Riley Culberg, lead author of the study published in the journal Nature Communications.
In the search for extraterrestrial life, Europa has attracted attention as one of the locales in our solar system that may be habitable, perhaps by microbes, owing to a global saltwater ocean detected deep beneath its ice shell.
Innumerable water pockets closer to the surface would represent a second potential habitat for organisms.
Europa is the fourth largest moon of Jupiter and is thought to have a substantial liquid water ocean under its 15 mile thick crust of ice
Ice-penetrating radar data revealed that refreezing of liquid subsurface water drove the formation of Greenland's double ridge, and if Europa's formed the same way, it could signal the presence of large amounts of liquid water near the surface
'The presence of liquid water in the ice shell would suggest that exchange between the ocean and ice shell is common, which could be important for chemical cycling that would help support life,' Culberg said.
'Shallow water in particular also means there might be easier targets for future space missions to image or sample that could at least preserve evidence of life without having to fully access the deep ocean.'
WHAT ARE DOUBLE RIDGES FOUND IN ICE FORMATIONS?
Jupiter's moon Europa is a prime candidate for extraterrestrial habitability in our solar system.
Double ridges are the most common surface feature on Europa and occur across every sector of the moon, but their formation is poorly understood.
Current hypotheses provide competing and incomplete mechanisms for the development of their distinct morphology.
A team from Stanford analyzed a double ridge in Northwest Greenland with the same gravity-scaled geometry as those found on Europa.
'Using surface elevation and radar sounding data, we show that this double ridge was formed by successive refreezing, pressurization, and fracture of a shallow water sill within the ice sheet,' they said.
If the same process is responsible for Europa's double ridges, the study suggests that shallow liquid water is spatially and temporally ubiquitous across Europa's ice shell.
This increases the possibility of finding evidence of life in these water pools.
NASA's robotic Europa Clipper spacecraft is scheduled for a 2024 launch to further investigate whether this moon possesses conditions suitable for life.
The shallow depth of Europa's potential water pockets - perhaps within six-tenths of a mile of the surface - also would place them near chemicals vital for the formation of life that may exist on its surface.
With a diameter of 1,940 miles, Europa is the fourth-largest of Jupiter's 79 known moons, a bit smaller than Earth's moon but bigger than the dwarf planet Pluto.
Europa's ocean may contain double the water of those on Earth. Life first emerged on Earth as marine microbes.
Europa's double ridges, sometimes extending hundreds miles (km), generally are around 490-650 feet tall, with the peaks about three- to six-tenths of a mile apart.
Scientists have debated how they formed. Culberg was struck by their resemblance to a landform he knew from northwestern Greenland, with peaks about 6.5 feet tall, separated by about 160 feet and extending about a half mile.
'The Greenland double ridge feature formed from the successive refreezing, pressurization and fracture of a near-surface water pocket,' Culberg said.
We see two ridges, rather than one, because the shallow water pocket was also split in two by a fracture filled with refrozen water.'
The water pocket in Greenland was about 50 feet below the surface, likely less than 33 feet thick and about a mile (1.6 km) wide.
If the same process spawned Europa's many double ridges, each associated water pocket could boast a volume similar to Lake Erie, one of North America's Great Lakes.
'Between having two potential habitats and the fact that double ridges - and the near-surface water bodies they may imply - are among the most common features on Europa's surface, it makes this moon a very exciting candidate for habitability indeed,' study co-author Dustin Schroeder added.
The study explored similarities between the elongated landforms, called double ridges, that are linear, with two peaks and a central trough between them, and slicing through one looks like a capital letter 'M'
On Earth, researchers analyze polar regions using airborne geophysical instruments to understand how the growth and retreat of ice sheets might impact sea-level rise.
Much of that study area occurs on land, where the flow of ice sheets is subject to complex hydrology – such as dynamic subglacial lakes, surface melt ponds and seasonal drainage conduits – that contributes to uncertainty in sea-level predictions.
Because a land-based subsurface is so different from Europa's subsurface ocean of liquid water, the study co-authors were surprised when they noticed that formations that streak the icy moon looked extremely similar to a minor feature on the surface of the Greenland ice sheet – an ice sheet that the group has studied in detail.
'We were working on something totally different related to climate change and its impact on the surface of Greenland when we saw these tiny double ridges – and we were able to see the ridges go from 'not formed' to 'formed,' ' Schroeder said.
If Europa's features form the same way, this could signal the presence of copious amounts of liquid water - a key ingredient for life - near the surface of the thick outer ice shell of Jupiter's fourth largest moon
The co-authors said their explanation for how the double ridges form is so complex, they couldn't have conceived it without the analog on Earth.
'The mechanism we put forward in this paper would have been almost too audacious and complicated to propose without seeing it happen in Greenland,' Schroeder said.
The findings equip researchers with a radar signature for quickly detecting this process of double ridge formation using ice-penetrating radar, which is among the instruments currently planned for exploring Europa from space.
'We are another hypothesis on top of many – we just have the advantage that our hypothesis has some observations from the formation of a similar feature on Earth to back it up,' Culberg said.
'It's opening up all these new possibilities for a very exciting discovery.'
WHAT DO WE KNOW ABOUT EUROPA AND WHY IS IT SO SPECIAL?
Jupiter's icy moon Europa is slightly smaller than Earth's moon.
Europa orbits Jupiter every 3.5 days and is tidally locked - just like Earth's Moon - so that the same side of Europa faces Jupiter at all times.
It is thought to have an iron core, a rocky mantle and a surface ocean of salty water, like Earth.
Unlike on Earth, however, this ocean is deep enough to cover the whole surface of Europa, and being far from the sun, the ocean surface is globally frozen over.
Many experts believe the hidden ocean surrounding Europa, warmed by powerful tidal forces caused by Jupiter's gravity, may have conditions favourable for life.
Nasa scientists are on the verge of exploring Jupiter's ocean moon Europa for signs of alien life.
Europa is our best shot of finding biological life in the solar system, researchers say.
The space agency is priming two probes, including one that will land on its surface, to explore the distant moon in detail within the next decade, the agency says.
Breaking News in Search for Extraterrestrial Life: Evidence of Water Near Europa’s Surface
Breaking News in Search for Extraterrestrial Life: Evidence of Water Near Europa’s Surface
BySTANFORD UNIVERSITY
This artist’s conception shows how double ridges on the surface of Jupiter’s icy moon Europa may form over shallow, refreezing water pockets within the ice shell. This mechanism is based on the study of an analogous double ridge feature found on Earth’s Greenland Ice Sheet.
Credit: Justice Blaine Wainwright
Explanation for the formation of abundant features on Europa bodes well for the search for extraterrestrial life.
Jupiter’s moon Europa is a prime candidate for life in our solar system, and scientists have been fascinated by its deep saltwater ocean for decades. However, it is encased in an icy shell that could be miles to tens of miles thick, making sampling it a difficult task. Increasing evidence suggests that the ice shell is more of a dynamic system than a barrier – and an astrobiology site with potential habitability in its own right.
Ice-penetrating radar observations that captured the formation of a “double ridge” feature in Greenland suggest that the ice shell of Europa may have an abundance of water pockets beneath similar features that are common on the surface. The findings, which will be published in the journal Nature Communications today (April 19, 2022), may be compelling for detecting potentially habitable environments within the exterior of the Jovian moon.
“Because it’s closer to the surface, where you get interesting chemicals from space, other moons, and the volcanoes of Io, there’s a possibility that life has a shot if there are pockets of water in the shell,” said study senior author Dustin Schroeder, an associate professor of geophysics at Stanford University’s School of Earth, Energy & Environmental Sciences (Stanford Earth). “If the mechanism we see in Greenland is how these things happen on Europa, it suggests there’s water everywhere.”
Ice-penetrating radar data from Greenland suggests that shallow water pockets may be common within Europa’s ice shell, increasing the potential for detecting signs of habitability near the surface of Jupiter’s moon.
A terrestrial analog
On Earth, researchers analyze polar regions using airborne geophysical instruments to understand how the growth and retreat of ice sheets might impact sea-level rise. Much of that study area occurs on land, where the flow of ice sheets is subject to complex hydrology – such as dynamic subglacial lakes, surface melt ponds, and seasonal drainage conduits – that contributes to uncertainty in sea-level predictions.
Because a land-based subsurface is so different from Europa’s subsurface ocean of liquid water, the study co-authors were surprised when, during a lab group presentation about Europa, they noticed that formations that streak the icy moon looked extremely similar to a minor feature on the surface of the Greenland ice sheet – an ice sheet that the group has studied in detail.
“We were working on something totally different related to climate change and its impact on the surface of Greenland when we saw these tiny double ridges – and we were able to see the ridges go from ‘not formed’ to ‘formed,’ ” Schroeder said.
Upon further examination, they found that the “M”-shaped crest in Greenland known as a double ridge could be a miniature version of the most prominent feature on Europa.
A view of Europa created from images taken by NASA’s Galileo spacecraft in the late 1990s.
Credit: NASA/JPL-Caltech/SETI Institute
Prominent and prevalent
Double ridges on Europa appear as dramatic gashes across the moon’s icy surface, with crests reaching nearly 1000 feet, separated by valleys about a half-mile wide. Scientists have known about the features since the moon’s surface was photographed by the Galileo spacecraft in the 1990s but have not been able to conceive a definitive explanation of how they were formed.
Through analyses of surface elevation data and ice-penetrating radar collected from 2015 to 2017 by NASA’s Operation IceBridge, the researchers revealed how the double ridge on northwest Greenland was produced when the ice fractured around a pocket of pressurized liquid water that was refreezing inside of the ice sheet, causing two peaks to rise into the distinct shape.
Europa is the smallest of Jupiter’s four Galilean moons, and the sixth-closest to the planet of all the 80 known moons of Jupiter. It is also the Solar System’s sixth-largest moon. Galileo Galilei discovered Europa in 1610, and named it after Europa, the Phoenician mother of King Minos of Crete and Zeus’ lover (the Greek equivalent of the Roman god Jupiter).
“In Greenland, this double ridge formed in a place where water from surface lakes and streams frequently drains into the near-surface and refreezes,” said lead study author Riley Culberg, a PhD student in electrical engineering at Stanford. “One way that similar shallow water pockets could form on Europa might be through water from the subsurface ocean being forced up into the ice shell through fractures – and that would suggest there could be a reasonable amount of exchange happening inside of the ice shell.”
Snowballing complexity
Rather than behaving like a block of inert ice, the shell of Europa seems to undergo a variety of geological and hydrological processes – an idea supported by this study and others, including evidence of water plumes that erupt to the surface. A dynamic ice shell supports habitability since it facilitates the exchange between the subsurface ocean and nutrients from neighboring celestial bodies accumulated on the surface.
“People have been studying these double ridges for over 20 years now, but this is the first time we were actually able to watch something similar on Earth and see nature work out its magic,” said study co-author Gregor Steinbrügge, a planetary scientist at NASA’s Jet Propulsion Laboratory (JPL) who started working on the project as a postdoctoral researcher at Stanford. “We are making a much bigger step into the direction of understanding what processes actually dominate the physics and the dynamics of Europa’s ice shell.”
The co-authors said their explanation for how the double ridges form is so complex, they couldn’t have conceived it without the analog on Earth.
“The mechanism we put forward in this paper would have been almost too audacious and complicated to propose without seeing it happen in Greenland,” Schroeder said.
The findings equip researchers with a radar signature for quickly detecting this process of double ridge formation using ice-penetrating radar, which is among the instruments currently planned for exploring Europa from space.
“We are another hypothesis on top of many – we just have the advantage that our hypothesis has some observations from the formation of a similar feature on Earth to back it up,” Culberg said. “It’s opening up all these new possibilities for a very exciting discovery.”
Reference:
“Double ridge formation over shallow water sills on Jupiter’s moon Europa” 19 April 2022, Nature Communications. DOI: 10.1038/s41467-022-29458-3
Schroeder is also a faculty affiliate with the Institute for Human-Centered Artificial Intelligence (HAI), an associate professor, by courtesy, of electrical engineering and a center fellow, by courtesy, at the Stanford Woods Institute for the Environment.
This research was supported by a National Defense Science and Engineering Graduate Fellowship and, in part, by NASA Grant NNX16AJ95G and NSF Grant 1745137.
Official history tells us that 17 missions were launched between 1961 and 1975, of which 11 were manned (Apollo 7 through Apollo 17). During this time, 6 successful landings on the lunar surface were made. The Apollo 18, 19, and 20 flights were canceled due to the lack of new scientific value at the huge expense of the state budget and taxpayers. However, in 2007, Italian freelance journalist Luca Scantamburlo took a written interview with William Rutledge, who claims to be a member of the secret Apollo 20 mission.
According to him, he was an employee of Bell Laboratories and served in the US Air Force. Rutledge attracted public attention by starting to distribute photographs and videos of the Apollo 20 mission online in 2007 which captured the same spaceship and its pilots.
Alien Spaceship Found On Moon With Alien Bodies
What is the essence of the information from Rutledge? He claimed that during the Apollo 15 mission to the moon, an unidentified man-made object was discovered and photographed on its surface.
During missions 16 and 17, several more photographs were taken and reconnaissance of the terrain from orbit was carried out. The task of missions 18 and 19 (which was no longer officially) is not really clear: Rutledge only says that during these missions, a number of problems occurred, as a result of which research data was lost. It was originally planned to land next to an alien ship and study it using rovers.
Humanoid body found on the moon during Apollo 19&20
In 1976, the Apollo 20 mission was launched, which included: William Rutledge, Aleksei Leonov, and Leona Snyder. They managed to land by the ship, get inside, inspect the interior of the ship, and the bodies of the pilots. One of the sources said that they not only examined the bodies but also took the head of one of the bodies with them.
The dimensions of the ship were 3370 x 510 meters; the age is estimated at 1.5 billion years; inside, there are many signs of biological life: remnants of vegetation in the engine compartment of the ship, stones of a triangular shape that exude a yellow liquid that has some medical properties, the remains of small bodies (about 10 cm) that lived in a network of “glass” pipes piercing the whole ship.
Alien Spaceship
They found a humanoid, female, 1.65 meters. She had genitals, hair, six fingers (we assume the math is based on a dozen). She was a pilot, there was an aerobatics device connected to her fingers and eyes, the body had no clothes, and they had to cut two cables connected to the nose without nostrils. Leonov detached the device from the eyes. Blood clots or bio-fluids burst and froze in the mouth, nose, eyes, and parts of the body. Some parts of the body were in unusually good condition, hair and skin were protected by a thin transparent layer of protection. The condition seemed neither dead nor alive. The booth was full of inscriptions and formed from long, hollow hexagonal tubes.
Apollo 19 & 20 missions
On the other hand, one can only guess that this was the ship of the Anunnaki, about which Sitchin or some other guys wrote.
Doubts are caused by the number of fingers, these humanoids have 12 of them (6 on each hand), and we know that the Anunnaki used the hexadecimal numbering system and on all the frescoes, they have 5-fingered palms.
We also know that the Anunnaki had a parallel mission in low-Earth orbit: one part of them worked on Earth, the other part remained on the mother ship. It may well be that they used the moon and one of the ships remained there. Another interesting fact is that the team of engineers who actually implemented the Apollo project was headed by Wernher von Braun, who during Nazi Germany worked for the benefit of the Third Reich, creating for them the famous V-2 rockets.
Braun came to America along with many other German scientists removed from Germany as part of Operation Paperclip in 1945. And the colossal technological breakthrough of the engineers of the Third Reich happened due to cooperation with the occult societies of Ahnenerbe and Vril, who obtained information from the ancient egregors of the Gods related to our civilization.
Braun had an interesting chain of events: German occult societies -> moving to the USA -> working on a space program -> detecting an alien spacecraft, possibly the very same Gods who advised the Nazis. He survived until 1977 and saw the launch of Apollo 20 and, moreover, according to Rutledge, was personally present at the launch.
In recent weeks, the project took a big step forward with the installation of fiber optic amplifiers and splitters on all VLA antennas, which give COSMIC access to the data streams from the entire VLA. Once this digital backend is online, COSMIC will have access to all data provided by the VLAs 27 radio antennas, which will be able to conduct observations 24/7. In the process, COSMIC SETI will examine around 40 million stars in the Milky Way for possible signs of intelligent life.
Located in the deserts of New Mexico, the Karl G. Jansky Very Large Array is the world’s largest radio telescope array capable of operating at microwave frequencies. It was featured in the 1997 film “Contact” (based on the original novel by Carl Sagan), where Dr. Eleanor Arroway (played by Jodie Foster) and her colleagues received the first extraterrestrial communication. Interestingly enough, the VLA has never been part of a SETI effort in real life, but that’s about to change.
The end results of the EDFA/Cosmic fiber work. Credit: SETI Institute
Jack Hickish, Digital Instrumentation Lead for COSMIC SETI, explained in a SETI Institute press release:
“Having all the VLA digital signals available to the COSMIC system is a major milestone, involving close collaboration with the NRAO VLA engineering team to ensure that the addition of the COSMIC hardware doesn’t in any way adversely affect existing VLA infrastructure.
“It is fantastic to have overcome the challenges of prototyping, testing, procurement, and installation – all conducted during both a global pandemic and semiconductor shortage – and we are excited to be able to move on to the next task of processing the many Tb/s of data to which we now have access.”
As part of this collaborative effort, the VLA will conduct observations while SETI Institute scientists will analyze that data to look for evidence of technological activity (aka. “technosignatures”). The VLA offers many important capabilities for SETI, not the least of which are its size. Each of its 27 antennas measures 25 m (82 ft) in diameter, yielding a collecting area equivalent to a single-dish antenna measuring 130 m (426 ft) in diameter.
This surface area and large amounts of metal mesh allow for almost unparalleled sensitivity levels, which is always a plus for SETI surveys (where signals are likely to be weak). In addition, each VLA antenna has eight cryogenically cooled receivers that continuously monitor the sky at frequencies ranging from 1 to 50 GHz in the radio spectrum. Some receivers can operate between 1 GHz and 54 MHz, corresponding with frequencies used for television broadcasts.
SETI Institute Post-Doctoral Researchers, Dr. Savin Varghese, and Dr. Chenoa Tremblay, in front of one of the 82-foot diameter dishes that make up the Very Large Array. Credit: SETI Institute
To exploit these capabilities, engineers at the VLA have installed a “splitter” that feeds a copy of the data stream provided by the VLA’s 27 antennas to locally-installed SETI equipment. This equipment consists of software and hardware that computes 64 different beams, which sorts cosmic static into hundreds of millions of narrow-band frequency channels. Said Cherry Ng, a SETI Institute COSMIC Project Scientist:
“I am excited by the ability of COSMIC to conduct the most comprehensive technosignature search ever in the Northern Hemisphere. We will be able to monitor millions of stars with a sensitivity high enough to detect an Arecibo-like transmitter out to a distance of 25 parsecs (81 light-years), covering an observing frequency range from 230 MHz to 50 GHz, which includes many parts of the spectrum that have not yet been explored for ETI signals.”
The COSMIC SETI program, which is expected to be operational by early 2023, will observe around 40 star systems in our galaxy over two years. It will be the most comprehensive SETI survey undertaken in the Northern Hemisphere, a record previously held by Breakthrough Listen. Its first major observational campaign will be conducted in parallel with the ongoing VLA Sky Survey (VLASS), which relies on the VLA to survey 82% of the sky in the 2-4GHz S-bands.
“We look forward to partnering with the SETI Institute on this exciting initiative and are pleased to see this important milestone in the technical work that will make this new science possible,” said NRAO Director Tony Beasley.
In this series we are exploring the weird and wonderful world of astronomy jargon! You’ll be the biggest thing in town after today’s topic: galaxy clusters!
Galaxy clusters are the single largest gravitationally bound structures in the Universe. The “gravitationally bound” part means that the gravity of the individual components of a galaxy cluster is strong enough to hold it together. While larger structures, known as superclusters, exist, they are not gravitationally bound and will eventually disperse.
Galaxy clusters can host a thousand galaxies or more and are typically at least 3-4 million light-years in diameter. The smallest galaxy clusters weigh 1014 solar masses, while the largest are ten to a hundred times more massive.
By far the dominant component of every galaxy cluster is dark matter, the mysterious form of matter that is invisible to light and does not interact with normal matter. Dark matter makes up around 90% of the mass of every cluster.
Of the remainder, 90% is in the form of an extremely hot but incredibly thin plasma called the intracluster medium. This medium is so hot that it emits brightly in the X-ray part of the electromagnetic spectrum. Even though the intracluster medium is so hot, it would register as a vacuum in Earth-based laboratory experiments.
Only 1% of the mass of every galaxy cluster is in the form of galaxies themselves. Those galaxies typically move through the cluster like bees in a beehive with speeds of up to a thousand kilometers per second. Those speeds can be used to weigh the cluster – more massive clusters will support faster galaxy movements without the cluster breaking apart.
The nearest cluster to Earth is the Virgo Cluster, which contains 1,000-2,000 galaxies and sits about 50 million light-years away.
Another famous cluster is the Coma Cluster, about 321 million light-years away. The main galaxies of the cluster are visible in amateur telescopes. In 1933 the astronomer Fritz Zwicky used observations of galaxy motion within the Coma Cluster to discover the existence of dark matter.
In this series we are exploring the weird and wonderful world of astronomy jargon! You’ll be off to a good start with today’s topic: the big bang theory!
The Big Bang theory is the current best understanding of the history of the Universe. The theory is a physical model, based on many lines of evidence, that says that our Universe was once smaller, hotter, and denser than it is today. In fact, according to our best measurements, about 13.77 billion years ago our entire observable Universe – including every star and galaxy that we could ever see – was once crammed into a tiny volume only a few centimeters across with a temperature of over a quadrillion degrees.
The Big Bang theory originated in the early 20th century. The first hints of the theory began with Einstein’s general theory of relativity. When he applied his equations to the study of the whole Universe, he found that a static, unchanging cosmos was highly unusual. Instead, the Universe should be either expanding or contracting. The Belgian astronomer and Catholic priest Georges Lemaître came to a similar conclusion, calling his idea of the origins of the Universe the “primeval atom.”
Scientists, including Einstein, rejected this idea. But in the 1920’s astronomer Edwin Hubble conclusively demonstrated that all galaxies are, on average, racing away from each other. The simplest explanation of this observation is that we live in an expanding Universe.
Since then, multiple lines of evidence have led scientists to conclude that the Big Bang theory is accurate. For example, models of the very early Universe successfully predict the abundance of light elements like hydrogen and helium. Early cosmologists also predicted the existence of an afterglow light pattern generated when the young Universe transitioned from a plasma to neutral state. This pattern, called the cosmic microwave background, was discovered on accident in the 1960’s.
In the Big Bang model, the primordial Universe expanded and cooled, eventually giving rise to the formation of stars and galaxies.
Today, no other theory of cosmology can successfully explain the wealth of evidence.
UFO Seen Over Las Vegas, Nevada 4-18-2022, UFO Sighting News.
UFO Seen Over Las Vegas, Nevada 4-18-2022, UFO Sighting News.
Date of sighting: April 18, 2022
Location of sighting: Las Vegas, Nevada, USA
Watch this amazing catch in Las Vegas, Nevada a few days ago. An eyewitness heard something loud that sounds like a jet and opened his phone to record, just in time to catch a strange object passing overhead. The object sounds like a jet, but looks alien made. I believe this craft could be one of USAF top secret evolutions of the TR3B, which started out as a triangle, but may have evolved into a new generation of spheres. Nellis AFB is in Las Vegas outskirts, and is a known testing ground for alien tech. Watch the video and its slow motion close up I made at the end. I have never seen a man made craft that looks like this before, and I worked on the flight line on B-1 bombers at Ellsworth AFB long ago.
UFO Near Space Station During Space Walk, April 18, 2022, HD Video, UFO Sighting News.
UFO Near Space Station During Space Walk, April 18, 2022, HD Video, UFO Sighting News.
Date of sighting: April 18, 2022
Location of sighitng: Space Station Source:NASA Live Cams
Now this is really confusing at what this could be. I know its not the SpaceX capsule because it would not be docking or leaving while there is a space walk going on, because it would jeopardize the safety of the astronauts. I also know that this is not the moon, since I have watched this cam for over 15 years and have seen the moon many times, it much bigger than this. This object has the shape and color of an alien craft. Notice how it hangs back, watching the astronauts do a space walk from a distance. Perhaps they are there not only to observe, but to lend a hand in case of emergencies. If the spacewalk goes bad, an astronaut could die before he or she gets back into the space station. These aliens are clearly not trying to hide, and yet, not trying to frighten the astronauts.
Tunnel Cloud, A UFO Freeway Within, Babylon, New York, April 14, 2022, UFO Sighting News.
Tunnel Cloud, A UFO Freeway Within, Babylon, New York, April 14, 2022, UFO Sighting News.
Date of sighting:April 14, 2022
Location of sighting: Babylon, New York, USA
Wow! This was seen not just in Babylon, New York but clear across New York along the waters edge, past Long Island. I have seen similar tunnels before. The tunnels are used by aliens as a transportation highway. The cloud is being contained by a forcefield that holds it together in a beam from one end to the other by maintenance UFOs. Then later larger orb UFOs often the size of city buses will transport through one after another with about a 2-3 minute space in between. This way, they move from one place on the planet to another unseen. There are many alien bases on Earth, not just one. There are said to be over ten thousand bases here. So UFOs are necessary to carry supplies, people, dignitaries and items back and forth. I'm sure many will doubt me on this, but I stake not only my reputation on this being true, but a similar sighting I personally had in the USAF at Rapid City, South Dakota back in 1990 is why I am reporting UFOs today. And yes, I saw four such tunnels starting above our parking lot, on a clear blue sky day. Each tunnel side by side. Not a cloud in the sky, but the tunnels. Then a grumbling noise and a huge 747 ball lit up at the end right above me. Then it slowly moved down the tunnel, increasing speed faster and faster until it disappeared over the horizon within the tunnel. Then another would appear in a tunnel next to it, and it all started again and again over 25X but I had to got to work at Ellsworth AFB so I'm sure I missed some. True story, like it or not. Its 100% real.
The quake was so ruinous, humans fled the area for 1,000 years.
The earthquake sent waves as high as 66 feet 5000 miles across the Pacific Ocean.
(Image credit: Shutterstock)
Archaeologists have found evidence of the largest known earthquake in human history — a terrifying magnitude-9.5 megaquake that caused a 5,000-mile-long (8,000 kilometers) tsunami and prompted human populations to abandon nearby coastlines for 1,000 years, a new study finds.
The earthquake struck about 3,800 years ago in what is now northern Chile when a tectonic plate rupture lifted the region's coastline. The subsequent tsunami was so powerful, it created waves as high as 66 feet (20 meters) and traveled all the way to New Zealand, where it hurled car-size boulders hundreds of miles inland, the researchers found.
Until now, the largest earthquake ever recorded was the 1960 Valdivia earthquake, which hit southern Chile with a magnitude between 9.4 and 9.6, killing up to 6,000 people and sending tsunamis barreling across the Pacific Ocean. The rupture that caused the Valdivia earthquake was enormous, extending as far as 500 miles (800 km) in length. But, as scientists detail in research published April 6 in the journal Science Advances, the newly discovered ancient megaquake was even bigger, coming from a rupture roughly 620 miles (1,000 km) long.
"It had been thought that there could not be an event of that size in the north of the country simply because you could not get a long enough rupture," study co-author James Goff, a geologist at the University of Southampton in England, said in a statement.
Like the Valdivia earthquake, the ancient quake was a megathrust earthquake, the most powerful type of earthquake in the world. These earthquakes occur when one of Earth's tectonic plates gets forced, or subducted, underneath another. The two plates eventually get locked into place by friction, but the forces that caused the plates to collide continue to build. Eventually, so much strain gathers that the point of contact between the plates rips apart, creating a gigantic rupture and releasing energy in the form of devastating seismic waves.
Evidence for the giant quake was found in marine and coastal items — such as littoral deposits (boulders, pebbles and sand native to coastal regions) and marine rocks, shells and sea life — that the researchers discovered displaced far inland in Chile's Atacama Desert.
"We found evidence of marine sediments and a lot of beasties that would have been living quietly in the sea before being thrown inland," Goff said in the statement. "And we found all these very high up and a long way inland, so it could not have been a storm that put them there."
To get a better sense of what brought these deposits so far from the sea, the researchers used radiocarbon dating. This method involves measuring the quantities of carbon 14, a radioactive carbon isotope, found inside a material to determine its age. As carbon 14 is everywhere on Earth, deposits easily absorb it while they form. The half-life of carbon 14, or the time it takes for half of it to radioactively decay, is 5,730 years, making it ideal for scientists who want to peer back into the last 50,000 years of history by checking how much undecayed carbon 14 a material has.
After dating 17 deposits across seven separate dig sites over 370 miles (600 km) of Chile's northern coast, the researchers found that the ages of the out-of-place coastal material suggested that it had been washed inland some 3,800 years ago.
Further evidence also came in the form of ancient stone structures that the archaeologists excavated. These stone walls, built by humans, were found lying beneath the tsunami's deposits, and some were lying backward, pointing toward the sea, suggesting that they had been toppled by the strong currents of the tsunami's backwash.
"The local population there were left with nothing," Goff said. "Our archaeological work found that a huge social upheaval followed as communities moved inland beyond the reach of tsunamis. It was over 1,000 years before people returned to live at the coast again, which is an amazing length of time given that they relied on the sea for food.
As this is the oldest known discovery in the Southern Hemisphere of an earthquake and tsunami devastating human lives, the researchers are excited to probe the region further. They think their research could better inform us of the potential dangers of future megathrust quakes.
"While this had a major impact on people in Chile, the South Pacific islands were uninhabited when they took a pummeling from the tsunami 3,800 years ago," Goff said. "But they are all well-populated now, and many are popular tourist destinations. So when such an event occurs next time, the consequences could be catastrophic unless we learn from these findings."
Wetenschappers vinden bewijzen van mogelijk zwaarste aardbeving die de mens ooit meemaakte
De sterkste aardbeving ooit gemeten was tot nu toe die van Valdivia in Zuid-Chili op 22 mei 1960. De beving had een kracht van ongeveer 9,5 op de momentmagnitudeschaal. Maar wetenschappers hebben nu bewijzen gevonden van een nóg grotere mega-aardbeving op onze planeet. Die vond zo’n 3.800 jaar geleden plaats in het noorden van Chili en is, voor zover geweten, de zwaarste die de mensheid ooit te verwerken kreeg.
Als gevolg van de Valdivia-aardbeving borrelden verwoestende tsunami’s op uit de Stille Oceaan. In totaal lieten zo’n 6.000 mensen het leven bij de megabeving. De enorme breuklijn die de aardbeving veroorzaakte, strekte zich uit over een lengte van 800 kilometer.
De nieuw ontdekte megabeving uit de oudheid, beschreven in een artikel in het wetenschappelijke tijdschrift ‘Science Advances’, was het gevolg van een breuklijn die nóg langer was: ruwweg 1.000 kilometer. De bewuste aardbeving vond ongeveer 3.800 jaar geleden plaats in wat nu het noorden van Chili is.
De kustlijn werd toen opgetild door subductie, een fenomeen waarbij een tektonische plaat van de aarde onder een andere schuift. De twee platen worden op hun plaats gehouden door wrijving, maar de krachten die de platen hebben doen botsen, blijven toenemen. Uiteindelijk zal het contactpunt tussen de platen uit elkaar scheuren, waardoor er een gigantische breuk ontstaat en er energie vrijkomt in de vorm van verwoestende seismische golven.
3.800 jaar geleden leidde de aardbeving tot tsunamigolven met hoogtes van 20 meter, die zelfs tot Nieuw-Zeeland reikten, meer dan 8.000 kilometer verderop. Volgens de onderzoekers werden daar rotsblokken zo groot als auto’s tot honderden kilometers landinwaarts geslingerd.
De megabeving had een kracht van 9,5 op de momentmagnitudeschaal, de verbeterde schaal van Richter. De mensheid zou nadien de kustregio duizend jaar lang mijden.
Bewijzen voor die reusachtige aardbeving vonden wetenschappers in zee- en kustafzettingen, in zeegesteenten, schelpen en ander marien leven. De onderzoekers troffen dat soort afzettingsmateriaal ver landinwaarts aan in de Chileense Atacamawoestijn. “We vonden bewijs van mariene sedimenten en een heleboel beestjes die rustig in de zee zouden hebben geleefd tot ze op het land werden geworpen”, verduidelijkt geoloog James Goff, die meeschreef aan de studie. “En we vonden ze allemaal heel hoog en ver landinwaarts, wat betekent dat het geen storm kan zijn geweest die ze tot daar heeft gebracht.” Dat het 3.800 jaar geleden is dat die mariene afzettingen naar een onnatuurlijke plaats landinwaarts werden gedreven, konden de onderzoekers berekenen via koolstofdatering. Die moderne dateringsmethode werd toegepast op zeventien afzettingen, aangetroffen op zeven afzonderlijke opgravingsplaatsen, verspreid over een afstand van 600 kilometer langs de noordkust van Chili.
Een ander bewijs bestaat uit oude stenen muren, gebouwd door mensen en opgegraven door de archeologen. Ze zaten verborgen onder de afzettingen van de tsunami en lagen soms achterover in de richting van de zee, wat erop wijst dat ze zijn omgevallen door de sterke stroming, veroorzaakt door de terugslag van de tsunamigolven.
Volgens Goff trok de bevolking, die niets meer had, na de tsunami landinwaarts. Pas meer dan duizend jaar later zouden mensen de kuststreek weer opzoeken om er te gaan wonen. “Dat is een verbazingwekkend lange tijd, want ze waren voor hun voedsel afhankelijk van de zee”, legt Goff uit. Hij voegt eraan toe dat de gigantische aardbeving weliswaar zware gevolgen had voor de Chileense bevolking, maar dat de eilanden in de Stille Zuidzee 3.800 jaar geleden nog onbewoond waren. Dat is vandaag anders. “Ze zijn nu allemaal goed bevolkt en het zijn vaak ook populaire toeristische bestemmingen”, zegt de wetenschapper, die daarom de regio verder wil bestuderen. “Als zo’n gebeurtenis zich nog eens zou voordoen, kunnen de gevolgen catastrofaal zijn, tenzij we van onze bevindingen leren.”
Jupiters maan Europa bevat mogelijk water waarin leven kan bestaan, zeggen wetenschappers
Wetenschappers zijn ervan overtuigd dat Jupiters maan, Europa, mogelijk water bevat waarin leven kan bestaan. Dat stellen ze vast nadat ze oppervlaktekenmerken vonden die vergelijkbaar zijn met die op de Groenlandse ijskap. Ondergrondse poelen met zout water kunnen er heel reëel zijn, zeggen de onderzoekers die geloven dat de plaatsen veelbelovende plekken kunnen zijn om te zoeken naar tekenen van leven buiten de aarde.
Het bewijs voor de ondiepe poelen, niet ver onder het bevroren oppervlak van de maan, kwam aan het licht toen wetenschappers van Stanford opmerkten dat reusachtige parallelle bergkammen die zich honderden kilometers uitstrekken op Europa, opvallend veel leken op een veel kleinere dubbele bergkam die ze in het noordwesten van Groenland hadden gezien. De bergkammen van Europa kunnen tot 300 meter hoog zijn en worden gescheiden door valleien van een halve mijl (805 meter) breed.
Gewapend met radar- en andere waarnemingen van de Groenlandse bergkammen, begonnen ze te begrijpen hoe die zijn ontstaan. “Op de Groenlandse ijskap is een kleine dubbele bergkam te zien die bijna precies lijkt op de bergkammen die we op het oppervlak van Jupiters maan Europa zien”, zegt Riley Culberg, een promovendus en geofysicus aan Stanford. “En de reden dat het opwindend is om deze analoge eigenschap in Groenland te hebben, is dat we al ongeveer 20 jaar proberen te achterhalen wat juist de dubbele richels op Europa maakt.”
Als de bergkammen die de maan doorkruisen op dezelfde manier zijn gevormd als die op Groenland, dan is de kans reëel dat er zich ondergronds water op het hemellichaam bevindt. En dat biedt dan weer de mogelijkheid tot leven buiten de aarde. “Vloeibaar water dicht bij het oppervlak van de ijskap is echt een veelbelovend teken als we zoeken naar plaatsen waar leven een kans kan krijgen”, zei Dustin Schroeder, universitair hoofddocent geofysica aan de Stanford Universiteit.
Via breuken in de ijsschelp
Europa is iets kleiner dan de maan van de aarde en is 2.000 mijl (ongeveer 3.220 km) breed. Het werd een belangrijke kanshebber in de zoektocht naar leven elders toen waarnemingen van telescopen op de grond en passerende ruimtesondes bewijs vonden van een diepe oceaan 10 tot 15 mijl (16 tot 24 km) onder zijn ijzige oppervlak. Europa’s oceaan is naar schatting 40 tot 100 mijl diep (65 tot 160 km), dus ook al is hij maar een kwart zo breed als de aarde, hij kan toch twee keer zoveel water bevatten als alle oceanen van de aarde bij elkaar.
In ‘Nature Communications’ beschrijven de onderzoekers hoe de dubbele ijsruggen van Groenland, die ongeveer 50 keer kleiner zijn dan die op Europa, zijn ontstaan toen ondiepe plassen water onder de grond bevroren en het oppervlak keer op keer brak, waardoor de dubbele ruggen gestaag omhoog werden gestuwd. “Het is alsof je een blikje frisdrank in de vriezer zet en het ontploft. Het is dat soort druk dat de bergkammen aan het oppervlak omhoog duwt”, stelt Culberg.
In Groenland loopt het water vanuit de meren aan het oppervlak naar de ondergrondse zakken, maar op Europa vermoeden de wetenschappers dat vloeibaar water vanuit de onderliggende oceaan via breuken in de ijsschelp naar het oppervlak wordt geperst. Deze beweging van het water zou kunnen helpen bij de circulatie van chemische stoffen die nodig zijn voor leven in Europa’s oceaan, zo voegen zij eraan toe.
Europa Clipper-missie van de NASA moet duidelijkheid brengen
Michael Manga, professor in de aard- en planeetwetenschappen aan de Universiteit van Californië, Berkeley, die niet bij het onderzoek betrokken was, zegt dat het “aannemelijk” is dat Europa’s richels ontstaan door water dat omhoog wordt geperst. Maar er blijven vragen. “Ik vraag me af waarom de kenmerken op aarde zoveel kleiner zijn”, zegt hij. Hoewel de sterkere zwaartekracht van de aarde zou kunnen verklaren waarom de bergkammen hier lager zijn dan op Europa, is het onduidelijk waarom de valleien tussen de bergkammen ook smaller zijn.
Verwacht wordt dat de Europa Clipper-missie van de NASA, die in 2024 wordt gelanceerd, meer licht zal werpen op de manier waarop de dubbele bergkammen zijn ontstaan wanneer zij een gedetailleerde verkenning van Jupiters maan uitvoert en onderzoekt of zich daar omstandigheden bevinden die geschikt zijn voor leven.
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Massive Black Cube UFO appears above the Sun's Surface
Massive Black Cube UFO appears above the Sun's Surface
On April 15, 2022 the black cube UFO arrives next to the sun and reappears on April 17, 2022 but this time above the surface of the sun.
According to NASA, the black cubes are, in fact, missing data in the pictures but since flares of the sun partially cover the left side of the cube, we assume that the object appears to be real.
Curiously, a similar event occurred nine years earlier in the same month, just a coincidence?
The researchers think that there was a 'backwards universe' before the Big Bang that was then inverted to create the universe we live in today.
They explained: "We investigate the idea that the universe before the Big Bang is the CPT reflection of the universe after the bang, both classically and quantum mechanically."
And, added: "The universe before the bang and the universe after the bang may be viewed as a universe/anti-universe pair, emerging directly into the hot, radiation-dominated era we observe in our past.
"This, in turn, leads to a remarkably economical explanation of the cosmological dark matter."
The wild theory could mean the presence of dark matter in our universe isn't so mysterious after all.
The scientists propose dark matter is actually made up of a type of ghostly particle called right-handed neutrinos.
Neutrino particles are present in our universe but they only spin to the left.
Scientists think it's odd that they haven't found a version that spins to the right as the laws of physics suggest they should be out there.
The researchers think the right spinning particles could be invisible in our universe and could just be represented by dark matter.
Little is known about dark matter in the universe other than it can not be seen but does have a physical effect on other objects.
Researchers think investigating neutrino particles and dark matter further could potentially be a step in proving the 'anti-universe' theory.
Scientists don't think we'd be able to visit the proposed 'anti-universe' because it technically happened before the Big Bang.
The link between CIA and UFO mystery is dated back to 1947. Since then, many CIA officials and the ex-US military personally propelled UFOlogy by giving shocking statements. Former CIA & US military officials such as R. James Woolsey, Derrel Sims, Lue Elizondo, David Fravor, etc. described how the existence of reality all around us that we are unable to perceive could be a major aspect of the UFO phenomenon.
Recently, two veteran CIA officers Jim Semivan & John Ramirez, who have expressed personal interest in UFO/UAP issues and cases, joined the George Knapp show to discuss the CIA’s role in the study of UFOs and their own experiences.
Jim Semivan spent 25 years with the CIA and then joined other former government insiders as part of Tom Delonge’s To the Stars Academy. He detailed how he was inducted into the CIA and learned spycraft, which takes years to master. The CIA works on a “need-to-know” principle, so when it came to UFOs, Semivan was not made specifically aware of research on this topic, though CIA analyst Kit Green was known for pursuing the paranormal.
Jim Semivan worked for 25 years as an Operations Officer for the CIA’s Directorate of Operations.
On Coast to Coast AM Semivan described his own alien-type encounters that occurred to him and his wife starting in 1990, in which beings showed up in their bedroom. The incident was authentic, and not a hypnagogic or dream state, he stipulated. The couple subsequently observed on-and-off poltergeist activity in their home, and more recently, he said he saw a hooded figure that resembled the Death Eater character from Harry Potter, who perhaps materialized to herald the death of a close friend. Semivan said he concurs with a remark made by Skinwalker Ranch researcher Colm Kelleher that the UFO phenomenon is a lot more than nuts & bolts and machines, as there are also psychic and biological elements that ratchet up the high strangeness. To the Stars’ investigation of “metamaterials” with odd isotopic ratios (possibly associated with UFOs) was ongoing, he added.
In the first half of the interview Semivan said:
“I think they mention that the phenomenon is a natural part of our universe, and we’re living in it but we don’t recognize it. The same way that insects and animals don’t recognize the human universe. A cat and a dog could be running through a library, but they don’t have the faintest idea what the books are all about and what libraries are all about. We might be walking through our existence and there’s a whole other reality that surrounds us that we just simply don’t have the ability to see or interact with.”
“It seems to be peeking inside our little consensus reality. As I explained to somebody once, it comes close, it teases us, it cajoles us, it lies to us, but you can never take it home to meet the parents. It won’t allow you to do that. There’s no formal introduction. Add on top that there’s no ontology, which is just a fancy word, it basically means there’s no structure to even discuss this. We don’t have a common lexicon. Somebody said we have dots but no connections. I don’t even think we have dots.”
John Ramirez, a 25-year CIA veteran who specialized in ballistic missile defense systems, was featured in the latter half of the interview. He recalled his long-standing interest in spycraft, and how he shifted from being a Navy officer to the CIA in 1984. He compared intel gathering to being a journalist for a news service, though his sources for reports were typically clandestine.
John Ramirez
Like Semivan, he also experienced what might be considered alien abduction-type experiences, including being placed on an examination table in a circular craft. Interestingly, a number of his counterparts in the CIA and NSA also had UFO experiences, he revealed. In his job related to missile defense, he became aware of times when Russian radar would detect unusual craft, and in one instance, he said they tried to lure a UAP into landing.
Ramirez noted that CIA historian Gerald Haines wrote about the agency’s study of UFOs from 1947 through the 1990s, for a division that was initially called the Office of Scientific Intelligence. What was particularly intriguing to Ramirez was that the division had life sciences and medical people on staff, indicating possible interest in alien bodies.
He also described how an Air Force pilot on the plane that flew near Kamchatka to monitor Russian tests observed a massive “milky white wall” of light flying toward him at 6,200 mph, though the Air Force assumed it was some kind of countermeasure by the Russians. Regarding the military sightings of ‘trans-medium’ UAP like the Tic Tacs, Ramirez said he does not believe that Russia or any other foreign country has the capabilities to produce this kind of antigravity technology.
Lue made these points in several interviews, but in this one, he was asked to elaborate on his comments about how our senses are reductive and limit our reality, and how this might be relevant to the phenomenon. He replied:
“This is something we’ve been dealing with for a long time. Imagine the first person to get on a boat and sail over the horizon. There’s stories of sea monsters and Krakens that will devour you and destroy your boat. Yet, we did it anyways. We did sail, and we explored the world. It turns out, 500 years later, there really are sea monsters. We call them the Great Squid of the Pacific, and great white sharks and whales.
Now they’re just part of nature and have a scientific name, but those sea monsters still exist. They’re there, we just learned to understand them. Maybe this is the same thing. Maybe this is just another expedition over the horizon where we’re going to realize what we thought were monsters are really just neighbors.”
Interestingly, Garry Nolan, Lue Elizondo, Tom DeLonge, and Jacques Vallee say very similar things when it comes to the reality of the phenomenon.
New Horizons has sent back one of its most intriguing images of the surface of Pluto.
It shows a mysterious object appearing to 'slide' through the surface.
Nasa experts believe the object may be a 'dirty block of water ice'.
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Nasa experts believe the object may be a 'dirty block of water ice' which is floating in denser solid nitrogen. Also visible are thousands of pits in the surface, which scientists believe may form by sublimation.
WHERE IT WAS TAKEN
Transmitted to Earth on Dec. 24, this image from the Long Range Reconnaissance Imager (LORRI) extends New Horizons' highest-resolution views of Pluto to the very center of Sputnik Planum, the informally named icy plain that forms the left side of Pluto's 'heart' feature.
Sputnik Planum is at a lower elevation than most of the surrounding area by a couple of miles, but is not completely flat.
Its surface is separated into cells or polygons 10 to 25 miles (16 to 40 kilometers) wide, and when viewed at low sun angles (with visible shadows), the cells are seen to have slightly raised centers and ridged margins, with about 100 yards (100 meters) of overall height variation.
They say it is 'floating' in denser solid nitrogen, and which has been dragged to the edge of a convection cell.
Also visible are thousands of pits in the surface, which scientists believe may form by sublimation.
Transmitted to Earth on Dec. 24, this image from the Long Range Reconnaissance Imager (LORRI) extends New Horizons' highest-resolution views of Pluto to the very center of Sputnik Planum, the informally named icy plain that forms the left side of Pluto's 'heart' feature.
Sputnik Planum is at a lower elevation than most of the surrounding area by a couple of miles, but is not completely flat.
Its surface is separated into cells or polygons 10 to 25 miles (16 to 40 kilometers) wide, and when viewed at low sun angles (with visible shadows), the cells are seen to have slightly raised centers and ridged margins, with about 100 yards (100 meters) of overall height variation.
Mission scientists believe the pattern of the cells stems from the slow thermal convection of the nitrogen-dominated ices that fill Sputnik Planum.
A reservoir that's likely several miles or kilometers deep in some places, the solid nitrogen is warmed at depth by Pluto's modest internal heat, becomes buoyant and rises up in great blobs, and then cools off and sinks again to renew the cycle.
'This part of Pluto is acting like a lava lamp,' said William McKinnon, deputy lead of the New Horizons Geology, Geophysics and Imaging team, from Washington University in St. Louis, 'if you can imagine a lava lamp as wide as, and even deeper than, the Hudson Bay.'
Computer models by the New Horizons team show that these blobs of overturning solid nitrogen can slowly evolve and merge over millions of years. The ridged margins, which mark where cooled nitrogen ice sinks back down, can be pinched off and abandoned.
The 'X' feature is likely one of these—a former quadruple junction where four convection cells meet. Numerous, active triple junctions can be seen elsewhere in the LORRI mosaic.
Scientists from NASA’s New Horizons mission have also combined data from two instruments to create this composite image of Pluto’s informally named Viking Terra area.
Nasa also revealed new images of Pluto’s informally named Viking Terra area.
The combined data includes pictures taken by the spacecraft’s Long Range Reconnaissance Imager (LORRI) on July 14, 2015, from a range of about 31,000 miles (49,000 kilometers), showing features as small as 1,600 feet (480 meters) across.
Draped over the LORRI mosaic is enhanced color data from the Ralph/Multispectral Visible Imaging Camera (MVIC), gathered about 20 minutes after the LORRI snapshots were taken, from a range of 21,000 miles (34,000 kilometers) and at a resolution of about 2,100 feet (650 meters) per pixel.
The entire scene is 160 miles (250 kilometers) across.
Among the features scientists find particularly interesting are the bright methane ices that condensed on many crater rims; the collection of dark red tholins (small soot-like particles generated from reactions involving methane and nitrogen in the atmosphere) in low areas, like the bottoms of craters; and the layering on the faces of steep cliffs and on crater walls.
In areas where the reddish material is thickest and the surface appears smooth, the material seems to have flowed into some channels and craters. Scientists say tholin deposits of that thickness aren’t usually mobile on large scales, suggesting that they might be riding along with ice flowing underneath, or being blown around by Pluto’s winds.
The images are the latest to show mysterious 'pits' on the 'heart' of Pluto have been revealed in unprecedented detail, along with colour images of the dwarf planet's 'badlands'.
Mission scientists believe these mysterious indentations may form through a combination of ice fracturing and evaporation.
The scarcity of overlying impact craters in this area also leads scientists to conclude that these pits – typically hundreds of yards across and tens of yards deep – formed relatively recently.
Their alignment provides clues about the ice flow and the exchange of nitrogen and other volatile materials between the surface and the atmosphere.
On July 14 the telescopic camera on NASA's New Horizons spacecraft took the highest resolution images ever obtained of the intricate pattern of 'pits' across a section of Pluto's prominent heart-shaped region, informally named Tombaugh Regio. The image is part of a sequence taken by New Horizons' Long Range Reconnaissance Imager (LORRI) as the spacecraft passed within 9,550 miles (15,400 kilometers) of Pluto's surface, just 13 minutes before the time of closest approach.
The image is part of a sequence taken by New Horizons' Long Range Reconnaissance Imager (LORRI) as the spacecraft passed within 9,550 miles (15,400 kilometers) of Pluto's surface, just 13 minutes before the time of closest approach.
The magnified view is 50-by-50 miles (80-by-80 kilometers) across.
The large ring-like structure near the bottom right of the magnified view - and the smaller one near the bottom left - may be remnant craters.
The upper-left quadrant of the image shows the border between the relatively smooth Sputnik Planum ice sheet and the pitted area, with a series of hills forming slightly inside this unusual 'shoreline.'
Pictured here is the mountainous shoreline of Sputnik Planum. In this highest-resolution image from New Horizons, great blocks of Pluto's water-ice crust appear jammed together in the informally named al-Idrisi mountains. 'The mountains bordering Sputnik Planum are absolutely stunning at this resolution,' said New Horizons science team member John Spencer of the Southwest Research Institute
Nasa also revealed a new colourised version of the surface.
This enhanced color mosaic combines some of the sharpest views of Pluto that NASA's New Horizons spacecraft obtained during its July 14 flyby.
The pictures are part of a sequence taken near New Horizons' closest approach to Pluto, with resolutions of about 250-280 feet (77-85 meters) per pixel – revealing features smaller than half a city block on Pluto's surface.
Lower resolution color data (at about 2,066 feet, or 630 meters, per pixel) were added to create this new image.
The images form a strip 50 miles (80 kilometers) wide, trending (top to bottom) from the edge of 'badlands' northwest of the informally named Sputnik Planum, across the al-Idrisi mountains, onto the shoreline of Pluto's 'heart' feature, and just into its icy plains.
They combine pictures from the telescopic Long Range Reconnaissance Imager (LORRI) taken approximately 15 minutes before New Horizons' closest approach to Pluto, with – from a range of only 10,000 miles (17,000 kilometers) – with color data (in near-infrared, red and blue) gathered by the Ralph/Multispectral Visible Imaging Camera (MVIC) 25 minutes before the LORRI pictures.
This image reveals new details of Pluto's rugged, icy cratered plains, including layering in the interior walls of many craters. 'Impact craters are nature's drill rigs, and the new, highest-resolution pictures of the bigger craters seem to show that Pluto's icy crust, at least in places, is distinctly layered,' said William McKinnon, deputy lead of the New Horizons Geology, Geophysics and Imaging team
'The wide variety of cratered, mountainous and glacial terrains seen here gives scientists and the public alike a breathtaking, super-high-resolution color window into Pluto's geology,' Nasa said.
From its rugged 'badlands' to its mountainous shorelines, the latest pictures are part of a sequence taken 15 minutes before New Horizons' closest approach on July 14.
The science we can do with these images is simply unbelievable
The resolution is stunning. At around 80 metres per pixel, incredible details can be picked out, such as huge ice blocks, dramatic craters and crumpled ridges - all less than half the size of a city block on Pluto's diverse surface.
'These close-up images, showing the diversity of terrain on Pluto, demonstrate the power of our robotic planetary explorers to return intriguing data to scientists back here on planet Earth,' said John Grunsfeld, former astronaut and associate administrator for Nasa's Science Mission Directorate.
'New Horizons thrilled us during the July flyby with the first close images of Pluto, and as the spacecraft transmits the treasure trove of images in its onboard memory back to us, we continue to be amazed by what we see.'
These latest images form a strip 50 miles (80 km) wide on a world three billion miles away.
The pictures trend from Pluto's jagged horizon about 500 miles (800 km) northwest of the informally named Sputnik Planum, across the al-Idrisi mountains, over the shoreline of Sputnik, and across its icy plains.
'These new images give us a breathtaking, super-high resolution window into Pluto's geology,' said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado.
'Nothing of this quality was available for Venus or Mars until decades after their first flybys; yet at Pluto we're there already – down among the craters, mountains and ice fields – less than five months after flyby. The science we can do with these images is simply unbelievable.'
The images were captured with the telescopic Long Range Reconnaissance Imager (LORRI) aboard New Horizons, about 15 minutes before New Horizons' closest approach to Pluto – from a range of just 10,000 miles (17,000 km).
They were obtained with an unusual observing mode; instead of working in the usual 'point and shoot,' LORRI snapped pictures every three seconds while the Ralph/Multispectral Visual Imaging Camera (MVIC) aboard New Horizons was scanning the surface.
This mode requires unusually short exposures to avoid blurring the images.
These new images are six times better than the resolution of the global Pluto map New Horizons obtained, and five times better than the best images of Pluto's cousin Triton, Neptune's large moon, obtained by Voyager 2 in 1989.
Mission scientists expect more imagery from this set over the next several days, showing even more terrain at this highest resolution.
It follows an image released by Nasa last month showing 10 close-ups of the frosty, faraway world today, representing one Pluto day, which is equivalent to 6.4 Earth days.
Pictured are Pluto's 'Badlands'. This highest-resolution image from Nasa's New Horizons spacecraft shows how erosion and faulting have sculpted this portion of Pluto's icy crust into rugged badlands topography
NEW HORIZONS' NEW MISSION
The spacecraft that gave us the first close-up views of Pluto now has a much smaller object in its sights.
New Horizons is now track to fly past a recently discovered, less than 30-mile-wide object out on the solar system frontier.
The close encounter with what's known as 2014 MU69 would occur in 2019. It orbits nearly 1 billion miles (1.6 billion kilometers) beyond Pluto.
Nasa and the New Horizons team chose 2014 MU69 in August as New Horizons' next potential target, thus the nickname PT-1. Like Pluto, MU69 orbits the sun in the frozen, twilight zone known as the Kuiper Belt.
MU69 is thought to be 10 times larger and 1,000 times more massive than average comets, including the one being orbited right now by Europe's Rosetta spacecraft.
On the other end, MU69 is barely 1 percent the size of Pluto and perhaps one-ten-thousandth the mass of the dwarf planet. So the new target is a good middle ground, according to scientists.
The team plans to formally ask Nasa next year to fund the mission extension for studying MU69.
Scientists promise a better name before showtime on January 1, 2019.
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Over mijzelf
Ik ben Pieter, en gebruik soms ook wel de schuilnaam Peter2011.
Ik ben een man en woon in Linter (België) en mijn beroep is Ik ben op rust..
Ik ben geboren op 18/10/1950 en ben nu dus 73 jaar jong.
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