Oldest Tool Use Thrown Back To Two million Years In Oldupai Gorge Find

An interdisciplinary team of researchers have unearthed the oldest stone tools at the oldest archaeological site in the famous Oldupai Gorge, popularly known as the Cradle of Humankind. Their discoveries also reveal how the earliest hominins coped with climate change two million years ago.

An Acheulean hand-axe from the Olduvai Gorge is pictured in an undated file photo. 

PHOTO BY GERALD CORSI /iStock/Getty Images Plus

The new study is published in  Nature Communications  and provides an ecological perspective on early human adaptability two million years ago. It is focused on Ewass Oldupai - the oldest archaeological site in Oldupai (formerly Olduvai) Gorge. The study demonstrates how hominins adapted to the region’s diverse environmental conditions over a 200,000 year period.

New interdisciplinary field work has led to the discovery of the oldest archaeological site in Oldupai Gorge, which shows that early humans used a wide diversity of habitats amidst environmental changes across a 200,000 year-long period.

( Michael Petraglia )

Discoveries at Oldupai Gorge, the Famous Cradle of Humankind

Oldupai Gorge  is a very important paleoanthropological site located in Tanzania in the Great Rift Valley. For more than a century, researchers have been excavating in this area, and cumulatively they have found hundreds of fossils and stone tools which date back millions of years. The site was made famous by  Louis and Mary Leakey  and is a UNESCO World Heritage site.

EurekAlert! reports that, despite the long history of surveys and excavations at the Oldupai Gorge, there has been a lack of ecological studies associated with the cultural remains which have been found there. This allows the new study to cast light on the environmental contexts in which the early hominins lived.

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The study comes from an international and interdisciplinary team of researchers from the Max Planck Institute for the Science of Human History in Germany, the University of Calgary in Canada, and the University of Dar es Salaam in Tanzania. The researchers convened for excavations at the Ewass Oldupa and they have unearthed the oldest Oldowan stone tools ever found at Oldupai Gorge. The stone tools date from roughly 2 to 1.8 million years ago.

Excavations at Ewass Oldupa uncovered the oldest Oldowan stone tools ever found at Oldupai Gorge, dating to ~2 million years ago, and also unearthed fossils of mammals, reptiles and birds.

( Michael Petraglia )

Remaining Stable in Changing Environments

Paleoanthropologists at the site studied fossils from a variety of animals, including primates, wild cattle and pigs, hippos, panthers, lions, hyenas, reptiles, and birds. They found that over 200,000 years, the habitat changed and included fern meadows, woodland mosaics, naturally burned landscapes, lakeside palm groves and dry steppe environments.

Outcrop geometry, stratigraphic architecture, and idealized vegetation at Ewass Oldupa. a) Post-eruptive, fern meadow. b) Coarse Feldspar Crystal Tuff  mosaics. c) Woodland with palms and ferns. d) Grasslands. e) Open woodland. f) Asteraceae-dominated scrub.

(Mercader, J. et al.  Nature 2021 )

The combined paleoanthropological and archaeological evidence shows that hominin activities recurred, but were periodically absent in the changing environment. Dr. Pastory Bushozi of Dar es Salaam University, Tanzania,  said that “the occupation of varied and unstable environments, including after volcanic activity, is one of the earliest examples of adaptation to major ecological transformations.”

Even though the environment was changing, the researchers found that the prehistoric hominin toolkits remained more or less the same. The iconic  Oldowan pebble and cobble cores, sharp-edged flakes, and polyhedral cobbles were still used to butcher animals and process plants, no matter how the habitat changed over the 200,000 years.

Who Made the Ewass Oldupa Tools?

You may be wondering by now which group of our prehistoric ancestors made the oldest Oldowan  stone tools  ever found at Oldupai Gorge. The possible toolmaker group is not certain, since no hominin fossils have been found at Ewass Oldupa yet, but it has been narrowed down to three possible hominin species.

Selection of stone tools from Ewass Oldupa.  

(Mercader, J. et al.  Nature 2021 )

One possibility is that  Homo habilis  created the tools. Their fossils have been found in 1.82-million-year-old deposits at a location just 350 meters (1148.29 ft.) away from Ewass Oldupa. Professor Julio Mercader of the University of Calgary  stated that “these early humans were surely ranging widely over the landscape and along shores of the ancient lake.”

But Mercader also noted that  australopithecines were also around Ewass Oldupa at the time and probably making and using stone tools in the area and members of the  Paranthropus genus also lived in Oldupai Gorge in the same time period; both of these groups could be not be ruled out as the prehistoric toolmakers.

Setting the Stage for Bigger Things

The researchers  write that their findings at Oldupai Gorge are “unique for this period and depicts complex behavior among early  Pleistocene hominins.” They explain  that the ability of the hominins to adapt to the changing environments at Oldupai Gorge prepared our prehistoric ancestors for bigger goals.

Combining the recent Oldupai Gorge discoveries with other finds across eastern Africa suggests that by 2 million years ago, hominins had the behavioral abilities they needed to expand into  new ecosystems , and they used those abilities. As Professor Michael Petraglia of the Max Planck Institute  noted that “This behavioural flexibility arose in the context of the dawn of the evolution of our own genus, Homo, and it set the stage for the eventual global, invasive  spread of Homo sapiens .”

• Top Image: The excavations uncovered the oldest Oldowan stone tools ever found at Oldupai Gorge, dating to ~2 million years ago.
• Source:  Michael Petraglia / Mercader, J. et al.,  Nature 2021

By Alicia McDermott

{ https://www.ancient-origins.net/ }

19-01-2021 om 00:23 geschreven door peter  

Titanoboa: The Monster Snake that Ruled Prehistoric Colombia

You may not want to read about this frightening creature if you suffer to any degree from ophidiophobia, or even if you are about to embark on a camping trip. Titanoboa fossils show it was the largest snake in the world. It lived during the Paleocene epoch, about 60 million years ago, so you are safe from its bone crushing grip now, but the image of the huge prehistoric snake slithering around South America is still a terrifying one.

So far, the South American country of Colombia has the only known fossils of the huge serpent. It is through these few fossils that paleontologists were able to estimate the size of this prehistoric creature. This estimation was then used to create a life-size model of Titanoboa, which was exhibited in 2012 in New York City’s Grand Central Terminal as a promotion for the Smithsonian Channel documentary entitled Titanoboa: Monster Snake.

The "Titanoboa: Monster Snake" exhibit from the Smithsonian at the Natural History Museum.

(Ryan Quick/ CC BY 2.0 )

A Titanic Boa

Titanoboa simply means ‘titanic boa’ and is an apt name for this prehistoric snake. According to estimates made by paleontologists, it could have grown to a length of between 42 feet and 49 feet (between 12.8 meters and 14.9 meters) and weighed up to a massive 2500 pounds (1134 kg). In addition, the thickest part of the snake’s body is reckoned to have had a diameter of 3 feet (0.9 meters).

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As a comparison, the anaconda, one of the largest snakes today, is known to reach lengths of over 20 feet (6.1 meters) and weigh more than 500 pounds (227 kg). Titanoboa was obviously a giant compared to the largest snakes we have today.

Artistic representation of Titanoboa.

(tuomaskoivurinne/ Deviant Art)

Discovering Titanoboa

The discovery of Titanoboa was made during the first decade of the 21st century in Cerrejón, a coal mine in the northern part of Colombia. The campaign that led to the discovery began in 1994, when the Colombian geologist Henry Garcia found an unfamiliar fossil which he labelled as ‘Petrified Branch’ and placed it in a display case of the coal company.

In 2003, a Colombian undergraduate geology student by the name of Fabiany Herrera was at Cerrejón for a field trip when he discovered fossilized plant remains . As the area had not been explored previously by paleontologists, an expedition was soon organized. One of the researchers invited to join the expedition was Scott Wing, the curator of fossil plants at the Smithsonian’s National Museum of Natural History.

A Titanoboa vertebra dwarfs that of a modern 17-foot anaconda

( Brian Tietz )

It was Wing who realized that Garcia’s fossil was not from a plant. He sent photos of it to another expert, Jonathan Bloch, a paleontologist at the University of Florida. Bloch identified the fossil as part of a jawbone of a land animal.

This was exciting news, as fossils of terrestrial vertebrates from the Paleocene epoch had not been found in that part of South America before then. It was believed that more fossils of such animals were to be found at the site, and this proved to be true.

Identifying the Monster Snake

It was not until 2007, however, that the vertebra of a Titanoboa was identified, when a shipment of fossils labelled ‘crocodile’ was being inspected. When this discovery was made, fresh expeditions were conducted in the hopes of finding more vertebrae of this animal. Eventually, a total of 100 snake vertebrae from 28 animals were collected. With the vertebrae, the paleontologists were able to make estimations as to the size of the prehistoric snake.

Titanoboa with a dyrosaur and a turtle.

( Jason Bourque/University of Florida )

In 2012, another important discovery about the Titanoboa was made. This time, a snake skull was found. Such a find is extremely rare, as snake skulls are very fragile and usually fall apart after the animal dies.

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What Did Titanoboas Eat?

One of the peculiarities of this skull is that it has closely packed teeth, even more than modern day boas. This has led experts to speculate that Titanoboa was a specialized fish-eater. Still, considering its size, Titanoboa could have easily preyed on prehistoric turtles and crocodiles, which lived in the same habitat as this snake.

Titanoboa.

(darkwaterlilly/ Deviant Art )

These later discoveries prompted the 2012 creation of a life-size model of Titanoboa exhibited in New York City’s Grand Central Terminal to promote the Smithsonian Titanoboa documentary. Some people also believe that Titanoboas still live deep in the Amazon.

• Top Image: Titanoboa.
• Source: Michael Rosskothen /Adobe Stock

By Wu Mingren  

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{ https://www.ancient-origins.net/ }

18-01-2021 om 23:57 geschreven door peter  

The first comet to be found in 2021 – labeled C/2021 A1 (Leonard) – might become the brightest comet of this year! Charts and more info here.

This is what a comet looks like – just a dot to our eyes – when it’s far from the sun. Astronomers spotted Comet Leonard (inside the tick marks) in early January 2021, a year before its closest sweep past our sun. The comet might be visible to the unaided eye by the end of this year. 

Read more about this image, which is via astronomer Filipp Romanov.

Exciting news! A newly found comet might become 2021’s brightest comet. Astronomer Greg Leonard discovered the comet that now bears his name – C/2021 A1 (Leonard) – on January 3, 2021 at the Mount Lemmon Observatory in Arizona. Astronomers report that discovery images show a tail for the comet, suggesting we might see a nice tail as Comet Leonard draws closer to the Earth and sun. The comet is still far away, currently between the orbits of Jupiter and Mars, heading inward. It’ll reach perihelion, its closest approach to the sun, around January 3, 2022. And so we’ll have a whole year to watch this comet get brighter, and brighter!

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NASA/JPL estimates that Comet Leonard’s closest approach to Earth will be on December 12, 2021 (at around 14:13 UTC). Translate UTC to your time. It’ll pass Earth at the extremely safe distance of 21,690,493 miles (34,907,464 km).

Its orbit also suggests that the comet will then pass relatively close (about 2,632,000 miles) to planet Venus on December 18, 2021.

Estimates indicate it might reach a visual magnitude of around 5 or even 4 (the lower the brighter), and although at its brightest the comet will be very close to the horizon, we still might get very good views using binoculars during the days before closest approach to Earth, in early December 2021, with visibility to the eye alone still a possibility.

Nature provides us with sky events seen once in a lifetime. Comet Leonard might be one of these, as it seems to have a hyperbolic orbit, that is, an orbit that’ll carry it only once through the inner solar system, then out again into the depths of space.

In other words, after this current sweep close past our sun, Comet Leonard won’t be seen again from Earth.

This perspective on Comet C/2021 A1 (Leonard) shows its trajectory through our solar system. North is up. You can see that its orbit will cause it to be initially visible from Earth’s Northern Hemisphere, and then from the Southern Hemisphere.

Image via NASA/JPL.

This comet will be initially visible from the Northern Hemisphere, and will become visible from the Southern Hemisphere in December 2021 and January 2022.

Will Comet Leonard be visible to the unaided eye? It’s possible. This might be this year’s brightest comet (unless a new brighter one is discovered). It will provide a nice spectacle to observers using long exposure cameras, binoculars and even the smallest telescopes.

An amazing feature of this celestial visitor is that it’s an ultrafast comet; it’s traveling at 158,076 miles per hour (254,399 km/h or 70.6 km per second) relative to Earth.

Despite its incredible speed through the vast space of our solar system, don’t expect to see this comet swoosh across the sky. Like planets, comets do move in front of the star background, but only very slowly due to the large distances involved. Observers using telescopes will have to take a close look at the comet’s position relative to background stars, and compare the view five or 10 minutes later to detect its motion, because its great distance will cause it to appear as a very slow moving object.

Here are a few charts … and you might bookmark this post. We’ll be adding updates here.

Location of Comet C/2021 A1 (Leonard) on December 1, 2021. This chart is as seen from U.S., facing east about 90 minutes before sunrise. The Big Dipper asterism in the constellation Ursa Major the Great Bear will provide a good reference for observers to locate the comet. Illustration by Eddie Irizarry using Stellarium.

Comet C/2021 A1 is traveling so fast that its position in our skies will change daily during early December 2021. Here is its location on December 5, 2021, about 90 minutes before sunrise. Comet Leonard will be located very close to where we see bright star Arcturus, as seen here. Facing east, as seen from U.S. Illustration by Eddie Irizarry using Stellarium.

Location of Comet C/2021 A1 (Leonard) on December 10, 2021. By then, it will be brighter but closer to the horizon. As seen from U.S. about 30 minutes before sunrise.

Illustration by Eddie Irizarry, using Stellarium.

Around December 14-16, 2021, Comet C/2021 A1 (Leonard) will become visible just after sunset, very low in the southwest horizon, as seen from U.S.   See additional charts below:

Location of Comet C/2021 A1 (Leonard) on December 15, 2021, about 30 minutes after sunset.  Facing Southwest, as seen from U.S.   

Illustration by Eddie Irizarry using Stellarium.

 

On December 17, 2021, about 30 minutes after sunset, comet Leonard will be located below planet Venus. Facing Southwest, as seen from U.S.

Illustration by Eddie Irizarry using Stellarium.

December 19, 2021, about 30 minutes after sunset.  Facing Southwest, as seen from U.S.

Illustration by Eddie Irizarry using Stellarium.

• Bottom line: Comet C/2021 A1 (Leonard) – discovered on January 3, 2021 – is currently between the orbits of Jupiter and Mars, heading inward. It’ll reach perihelion, its closest approach to the sun, around January 3, 2022. We’ll have a whole year to watch this comet get brighter and brighter. It might become the brightest comet of 2021!

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{ https://earthsky.org/ }

18-01-2021 om 23:29 geschreven door peter  

Northern lights in Alaska.

Image via Manish Mamtani Photography.

Throughout human history, people have witnessed the aurora, both the northern and southern lights, and sought to explain and make sense of these dancing patterns in stories and myths.

In the modern world, science has revealed most of the secrets of the northern lights (aurora borealis) and southern lights (aurora australis). We understand that auroras form when solar particles collide with Earth’s upper atmosphere. Larger solar storms cause a greater influx of particles, which can cause auroras to reach lower latitudes and appear to a greater number of observers. The colors of the aurora are determined by which gases are excited by the solar plasma.

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All this scientific knowledge slowly started accumulating more than 2 1/2 centuries ago. But even now, when we look up at the trembling curtains of red, green or blue, a feeling of awe and mystery can pervade this ghostly show. It’s easy to see how many of these centuries-old myths referred to an otherwise unreachable world.

The folklore begins with the name “aurora” itself. Aurora is the Roman goddess of the dawn. The lights, usually starting as a subtle brightening on the northern horizon (in the Northern Hemisphere), appeared to be an out-of-place and untimely arrival of morning.

Image via Jörgen Norrland Andersson.

Tying the mystical lights to gods was an easy step for early cultures. The Algonquins on Manitoulin Island in Lake Huron thought an aurora was a sign of good will from their creator, Nanahbozho. The Chuvash of Siberia believed the aurora borealis was their heaven god helping women in childbirth.

One of the most common legends surrounding the northern lights concerned those who have passed into the Great Beyond. The people of the Six Nations Confederacy believed the northern lights showed the entry point to the Land of the Souls. The Vikings thought auroras were reflections from shields of the Valkyries, maidens who take dead warriors to Valhalla (heaven). The Salteaus of Eastern Canada and the Kwakiutl and Tlingit of southeastern Alaska all saw dancing souls in the flickering sky, sometimes of humans and sometimes of animals such as whales or seals. East Greenland Inuits viewed the lights as children who died at birth. In contrast to the many myths surrounding those who have passed on, the Lakota Sioux interpreted the lights as spirits of generations yet to be born.

View at EarthSky Community Photos. | David Kakuktinniq at Rankin Inlet, Nunavut, Canada, captured the aurora borealis and Mars on September 12, 2020. He wrote: “Northern lights over the Hudson Bay, with Mars near the center of the image.” Thanks, David!

Violence and war frequently made an appearance in these myths. The Sami people of northern Scandinavia believed that the souls of those who died a violent death made up the energy of the northern lights. Fox Indian tribes of Wisconsin feared the lights as ghosts of their slain enemies, trying to rise up again. For this reason, auroras were regarded as an omen of war and pestilence.

Another predominant story found in aurora myth involved games played with balls. Many Inuits’ myths involve the dead playing ball with a walrus head. The Wabanaki of Maine had a story of ball-playing people who had peculiar-colored lights on their heads and rainbow belts that resulted in the aurora.

Tying various animals to the lights was common around the world. Some Scandinavian people from medieval times saw the flickering lights and believed them to be caused by gigantic schools of herring in the sea, the light of their shimmering bodies reflected into the sky. One Finnish myth claims that foxes made of fire flung sparks into the air with their tails. Spotting the northern lights in China is less common, but a myth still evolved that these displays were the result of fire-breathing dragons.

The stunning Dragon Aurora appeared over Iceland in February 2019.

Copyrighted image via Jingyi Zhang & Wang Zheng.

The production of these lights was often blamed on mysterious groups of people who lived beyond the horizon. The Mandan of North Dakota told stories of people in northern nations using giant stew pots to simmer their dead enemies, the reflections of which were cast upon the sky. In Washington state, the Makah people also saw fires of those in the far north, only they spoke of a tribe of dwarves boiling blubber. Menominee Indians of Minnesota and Wisconsin thought the auroras were torches of friendly northern giants used in spearfishing at night. The Maori of New Zealand interpreted their glimpses of the aurora australis as reflected light from torches or campfires from previous generations who had traveled south and settled there.

Sometimes the northern lights figured into part of the weather forecast, as in the Penobscot of Maine believing an aurora foreteold windy weather. In Scotland, auroras are called “merry dancers.” Some believed that the quick motions of the dancers meant unsettled weather, while slow and graceful movements foretold favorable weather.

While we no longer blame auroras for a turn in the weather, they are a part of space weather. The sun can unleash a geomagnetic storm at any time, triggering another round of magnificent auroral displays. Watch the next event and decide for yourself what the lights mean to you.

• Bottom line: For millennia, people have viewed the southern and northern lights and created their own myths and folklore explaining the dancing lights they saw in the sky.

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18-01-2021 om 23:10 geschreven door peter  

Autonomous robot swarm swims like a school of fish

These underwater robots operate as a collective artificial intelligence.

 by Tibi Puiu

Researchers have devised a swarm of small fish-inspired robots that can synchronize their movements by themselves, without any human input. The autonomous robots essentially mimic the behavior of a school of fish in nature, exhibiting a realistic, complex three-dimensional collective behavior.

Each robo-fish (called a ‘Bluebot’) is equipped with cameras and sensors that enable it to track its neighbors and get a sense of direction. This is a step beyond the typical multi-robot communication system, in which individual bots have to communicate with each other via radio and constantly transmit their GPS data.

The team of engineers at Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering even mimicked a fish’s locomotion, opting for flapping fins instead of propellers. The fins actually improve the submersibles’ efficiency and maneuverability compared to conventional underwater drones.

“It’s definitely useful for future applications, for example, a search mission in the open ocean where you want to find people in distress and rescue them quickly,” Florian Berlinger, the lead author of a paper about the research that appeared in Science Robotics on Wednesday, told AFP.

Berlinger added that other applications for these cute underwater bots include environmental monitoring or the inspection of infrastructure.

Each robot measures just 10 centimeters (4 inches) in length and the casing is 3D printed. Their design was partly inspired by the blue tang fish, native to the coral reefs of the Indo-Pacific (Dora from Finding Nemo is a blue tang fish).

During a test, a swarm of Bluebots was inserted in a water tank with a light source and no other external input from the researchers. When one of the bots was the first to detect the light, its movements signaled to the others to gather around. The robots could operate similarly in a search-and-rescue mission, the researchers said.

Berlinger hopes to alter the design in the future so that the robo-fish don’t require LEDs to track the direction of the swarm. This way they could be used outside the lab for conservation projects, such as for coral reefs. Ultimately, this remarkable fit of engineering may also one day reveal hidden insights about collective intelligence in nature.

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{ https://www.zmescience.com/ }

18-01-2021 om 22:51 geschreven door peter  

A Secret Roswell Journal Becomes The Focus Of A New UFO Documentary

A secret journal offers new clues about the nature of the alleged 1947 AD UFO crash at Roswell in the New Mexico desert, or does it? Before we kick off, this isn’t one of these Reddit stories that emerged from some basement decorated with posters of the Starship Enterprise and Chewbacca. Quite the opposite.

Live Science is one off the internet’s more respected academic media outlets and today they tell the story of a hitherto unknown personal diary belonging to Major Jesse Marcel, a head intelligence officer at the Roswell Army Air Field. The secret Roswell journal could change the narrative of this famous UFO event. In particular, the secret Roswell journal may contain secret coded observations that will help to “clarify” what really happened in Roswell in 1947 AD.

Marcel investigated the famous Roswell site in New Mexico where in 1947 a UFO is believed by many to have crashed. Furthermore, he claimed to have recovered some of the debris from whatever ditched in the desert that July night near the Roswell Army Air Field (RAAF). Newspaper photos at the time showed Marcel with pieces of metallic material and on the afternoon of July 8, 1947 AD he disclosed to the media “the crash and recovery of a flying disc.” However, the following day, an army official made a statement saying that a weather balloon had fallen to earth, “not a flying saucer.”

This is a road sign near the original UFO crash site in Roswell. Hopefully, the secret Roswell journal of Major Jesse Marcel will reveal more about what “really” happened in New Mexico on that day!

Source: spiritofamerica / Adobe Stock

Will The Secret Roswell Journal Change Everything?

The Roswell story now takes a new turn since Major Marcel's family revealed they had kept his personal secret Roswell journal which contains “hitherto unknown clues about the crash.” The secret diary and its equally secret contents will soon be presented on History Channel´s History's Greatest Mysteries series in an episode called Roswell: The First Witness . The episode was released on December 12th, Saturday, 2020 AD. The show host, Ben Smith, is a former CIA operative and the show's lead investigator. He thinks it is very unusual that the day after the government claimed they had recovered a UFO they switched stories and maintained it was merely “a weather balloon,” Smith told Live Science .

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This story is another in a long line of recent reports pertaining to UFOs. According to The Guardian in 2017 AD a former Pentagon official confirmed the existence of a federal agency that had been “secretly investigating UFOs since 2007.” Then, in 2018, U.S. Navy pilots reported “three encounters with fast-moving UAP, or unidentified aerial phenomena” better known to us civies as UFOs. And building up this emerging alien narrative, officially declassified videos of these occurrences were published in April of this year, as previously reported on Live Science .

Secret Roswell Journal: A Problem Of Might, May And Could

Let´s now return to Major Jesse Marcel, the author of the secret Roswell journal. He investigated the site at Roswell and recovered what he believed to be debris from a flying saucer . In 1997 AD, Time published an article saying Marcel told an interviewer at the time that “he believed” the object that crashed in the New Mexico desert had extraterrestrial origins. Now, a forensic analysis of Marcel´s secret Roswell journal “could reveal” coded messages that he wrote about the crash at the time that it happened, Ben Smith said.

When it comes to UFOs and aliens there are believers and there are skeptics. But no one really knows.

( Alperium / Adobe Stock)

This application of the word “could” will no doubt have skeptics raging, because they all know what’s most probably coming here. If the diary really contained any actual evidence that the Roswell incident was nothing more than a collapsed weather balloon we would certainly have heard about it by now. Unless of course thousands of unpaid interns and staff at the network have all kept quiet, doubters can argue. Perhaps the skeptics greatest argument is presented in plain sight in the newspaper photograph of Marcel on the evening of the crash. To all but the most committed believers in extraterrestrials it is perfectly clear that Marcel is holding a piece of a crumpled (crashed) weather balloon.

When the History Channel episode airs and unavoidably “no evidence” of extraterrestrials is offered, perhaps then maybe some “believers” will consider the content of the Ancient Origins news article I wrote about this only last month.

A team of Oxford University researchers recently applied statistics to the question “are we alone” and concluded that “life on earth is probably a unique universal phenomena, and that it´s ‘extremely unlikely’ that any other intelligent life exists anywhere else in the universe.” This is a profound claim that sceptics love and believers loathe.

And the same extreme opinions are likely to flood across social media channels when the details of Major Marcel's secret Roswell journal are revealed.

• Top image: A UFO flying over the New Mexico desert. The secret Roswell journal may provide new information about what actually happened in Roswell in 1947 AD. ( aleciccotelli / Adobe Stock)

By Ashley Cowie

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{ https://www.ancient-origins.net/general }

18-01-2021 om 22:34 geschreven door peter  

18-01-2021 om 20:31 geschreven door peter  

The truth is in there! CIA declassifies TWO THOUSAND documents on UFOs dating back to 1970s that reveal a mysterious object was analyzed by agency's chief scientist in 1976

• A dossier with more than 700 files about Unidentified Aerial Phenomena (UAPs) was published on The Black Vault website on Thursday

• Black Vault founder John Greenewald Jr spent two decades suing the CIA to release the records and then scanning the pages one by one

• A DailyMail.com review of about one-tenth of the files in the Black Vault database revealed a few perplexing examples of UAP sightings

• One of the reports describes how seemingly urgent UFO information was hand-delivered to the CIA's deputy director for science and technology in 1976

• In another report, CIA officials discuss the possibility that UFOs were behind a 'mysterious blast' in the small Russian town of Sasovo in 1991

By MEGAN SHEETS FOR DAILYMAIL.COM 

A treasure trove of newly-unsealed CIA records has revealed chilling accounts of hundreds of UFO sightings across the globe dating back to the 1950s - along with international intelligence agencies' efforts to understand them.  

The XXXX dossier with nearly 3,000 pages of documents about Unidentified Aerial Phenomena (UAPs) - the government's official term for what are commonly called UFOs - was published on The Black Vault website last week.  

Thousands of paranormal enthusiasts have already started poring through the collection of more than 700 individual documents, according to Black Vault's founder John Greenewald Jr, who has spent the past two decades suing the CIA to release the records and then scanning the pages into his database one by one.  

The CIA purports that the files account for its 'entire' collection of declassified UAP intel, but Greenewald cautions that there's no way to verify that claim and has vowed to continue searching for further records.  

The dossier was released ahead of a June deadline for US intelligence agencies to reveal everything they know about UFOs to Congress under a clause slipped into the $2.3trillion coronavirus relief bill signed into law by President Donald Trump in December.   

An ongoing DailyMail.com review of the files has uncovered a bevy of perplexing - yet unverified - accounts of mysterious disks tracking across the sky, spewing beams of light across small towns, causing explosions and even a few claims of military officers confronting aliens that come out of outlandish vehicles.  

Other documents show correspondence between CIA officers about the UFO sightings. Sometimes the officers brush off observers' stories as purely superstitious, even when another explanation isn't clear. But in several instances the officers show genuine concern that perhaps something XXXXX is at play. 

Russian airliner crew describes coming within 50 kilometers of a yellow disk shooting beams of light in Belarus in 1985 

Many of the documents included in the Black Vault archive describe UFO sightings in the former Soviet Union - but this one is particularly detailed. 

An article from Moscow's Trud newspaper dated January 30, 1985, describes how an airline crew en route from Rostov, Russia, to Tallinn, Estonia, came upon what they perceived to be a UFO about 120 kilometers from Minsk, Belarus, at about 4am.  

The article dramatically recounts the incident from the perspective of the crew. 'Glancing over his portion of the sky, the copilot noticed a large star that was not flickering on his upper right. But this is no star, this yellow speck the size of a 5-kopeck coin, stretched out along the edges.

'"No matter..,"' he told himself calmly, "refraction of light in the atmosphere or something else..." A very thin beam of light emerged from the speck and fell vertically down to the ground itself.' 

The pilot nudged his three comrades in the cockpit and they watched as the 'beam of light suddenly opened up, turning into a luminous cone. ... A second cone emerged, wider, ... then a third one, broad and quite bright.' 

 The pilot recommended that they report the sight to the ground, but the commander stopped him, unsure of how they would even describe it.  

The men estimated that the object was only about 40 to 50 kilometers away. The copilot pulled out a paper to draw it before 'the beam of the "projector" rose from the ground and focused on the aircraft.'

'The commander was still hesitating: should he report what is taking place or not? But something that put an end to his doubts happened here. The white spot flashed up, and a green cloud emerged in its place.'

The commander recalled seeing the object rush toward his plane, before it suddenly disappeared. 'Well, now they will say we weren't in our right minds.' 

The article goes on to describe the crew's conversations with dubious ground controllers.  

It concludes with a statement from N. A. Zheltukhin, deputy chairman of the Commission on Aerodynamic Phenomena, who said: 'The commission is conducting a systematic study of [UFO] sightings over the territory of the Soviet Union. 

'However, we have to note that regrettably, all the accounts which we have at our disposal suffer from being one-sided or fragmentary to one degree or another.' 

Swedish pilot and flight mechanic spot a 'completely unorthodox, metallic object' flying at 'the speed of sound' outside Stockholm in 1953

A CIA report from April 1954 includes three newspaper articles about a purported UFO sighting five months earlier in Sweden. 

Captain Christiernsson and flight mechanic Olle Johansson were flying a Trasnair Airlines plane between Malmo and Stockholm on December 17, 1953, when the object appeared in the sky in front of them. 

'I do not doubt for an instant that it was not a jet plane,' Christiernsson told the Dagens Nyheter newspaper. 'What I saw was a completely unorthodox, metallic, symmetric, round object which was unlike anything I have seen before.  

'The silhouette was thin and it approached me at a very high velocity. Olle Johansson and I have discussed the matter of its speed, and we have estimated the speed to be about that of sound. The whole business took place fantastically quickly, but I believe that I was able to see the object for four to five seconds.' 

Johansson said: 'What I saw was an ellipse with sharp outlines and something between silver and white in color. It was approaching from the north in a direction opposite to ours, at a speed of about 1,200 kilometers per hour. It was flying entirely above the clouds. Since we had the automatic pilot on, we had no chance to turn quickly enough to see where the object went.' 

More than 700 declassified CIA reports about UFOs dating back to the 1970s were published on The Black Vault website on Thursday (file photo)

Urgent UFO information is hand-delivered to the CIA's top scientist for review in 1976 

Asked about which documents had piqued his interest, Greenewald highlighted a report about seemingly urgent UFO information being hand-delivered to an Assistant Deputy Director for Science & Technology at the CIA in April 1976. 

Most details about the information were redacted in the document, but Greenewald said he is determine to uncover more through further FOIA requests. 

The name of the deputy director was also redacted but records indicate that Carl Duckett served in that position at the time.  

The document states: 'We contacted A/DDS&T (Dr [redacted]) to see if he knew of any UFO program and also to answer the questions posed by [redacted]. 

'Dr [redacted] exhibited interest in [redacted] which was handcarried to his office. After a short examination of its contents Dr [redacted] advised us that he would personally look into the matter and get back to us.' 

A second document from June of 1976 appears to request an update on the review, but there is no record of the ordeal after that.  

The heavily redacted report above describes seemingly urgent UFO information being hand-delivered to an Assistant Deputy Director for Science & Technology in April 1976

CIA officials discuss the possibility that UFOs were behind a 'mysterious blast' in the small Russian town of Sasovo in 1991 

In another report, CIA officials discuss the possibility that UFOs were behind a 'mysterious blast' in the small Russian town of Sasovo - about 400 kilometers southwest of Moscow - in 1991. 

Residents reported seeing a 'fiery sphere' descend from the sky before a shockwave tore through the town, leveling an entire block. 

The report said investigators had failed to come to a conclusion about the cause of the explosion, leaving open the possibility of UFOs. 

It states: 'Some people are talking about munitions left buried since the last war, while others claim that a powerful bomb fell. A third group blame it on a meteorite, and a fourth group blame UFOs... There are people who supposedly saw a moving "fiery sphere".' 

Among the more than 700 files in the Black Vault database is this report, where CIA officials discuss the possibility that UFOs were behind a 'mysterious blast' in a small Russian town

UFO enthusiast hounds the CIA for information about a sighting at Ohio Air Force Base 

Several of the files appeared to reference the same incident, in which a possible UFO was sighted at the Wright-Patterson Air Force Base in Ohio in 1978. 

The reports refer to someone named Dr Leon Davidson who made multiple requests for information about the matter and did not appear to be getting any response. 

He is believed to be the same Dr Leon Davidson who studied UFOs for decades beginning in 1949, according to Columbia University, which was gifted a collection of the engineer's research on the subject after his death in 2007. 

One report states: '[Redacted] received a letter from Davidson [redacted] in which Davidson asked if the [redacted] tape had been analyzed at Wright Field.

'[Redacted] replied that the tape was forwarded to proper authorities for evaluation and no information was available concerning results. 

'[Redacted] then received a second letter dated 19 March from Davidson in which he said since [redacted] was not in a position to make enquires he would like the address of proper parties to make them to. 

'[Redacted] replied that he understood the proper address for forwarding information on "flying saucers" is Air Technical Intelligence Center, Wright Patterson Air Force Base. 

'Subsequently, [redacted] learned that Davidson made enquiries there. Apparently they stalled him.'

In May of that year another report asks: 'What progress has been made? This correspondence is more than a month old. I am afraid the longer we procrastinate the more fuel we add to the fire. Also, the people at Wright Field are holding their breaths awaiting advice.'

A third report, for which the date is illegible, says: 'Davidson is on our backs again. He wants a verbatim translation of the "space" message and the identification of the transmitter from which it came.'  

In a fourth report - which indicates that the case is 'closed' - the author states that Davidson was writing an article about the incident entitled: 'The Air Force and the Saucers, Part Three: The Central Intelligence Agency becomes involved with Saucers.'

It indicates that the CIA did provide Davidson with some information, but does not disclose what that information was. 

In the final report on the matter, the author indicates that the CIA will no longer be responding to Davidson's correspondence. 

Wright-Patterson AFB has long been linked to conspiracy theories about alien life, after serving as the headquarters of an Air Force program- dubbed 'Project Blue Book', which studied UFOs from 1947 to 1969.  

Over the course of those two decades the project garnered more than 12,600 reports of UFO sightings - 701 of which were never 'identified', according to the Dayton Daily News.  

Several of the files appeared to reference the same incident, in which a possible UFO was sighted at the Wright-Patterson Air Force Base in Ohio in 1978. The reports refer to someone named Dr Leon Davidson who made multiple requests for information about the matter and did not appear to be getting any response

In May of that year another report asks: 'What progress has been made?'

A third report, for which the date is illegible, says: 'Davidson is on our backs again. He wants a verbatim translation of the "space" message and the identification of the transmitter from which it came'

In a fourth report - which indicates that the case is 'closed' - the author states that Davidson was writing an article about the incident entitled: 'The Air Force and the Saucers, Part Three: The Central Intelligence Agency becomes involved with Saucers'

In the final report on the matter, the author indicates that the CIA will no longer be responding to Davidson's correspondence

UFO sighted in Morocco in 1976 

One of the most heavily-redacted documents reviewed by DailyMail.com is dated September 23, 1976, and features the words: 'To immediate director - with personal request to investigate UFO sighted in Morocco.' 

The full-page report is covered in 25 black lines that appeared to have been made directly with a pen. 

The report was first approved for release in February of 2010, a footnote indicates. 

One of the most heavily-redacted documents reviewed by DailyMail.com is dated September 23, 1976, and features the words: 'To immediate director - with personal request to investigate UFO sighted in Morocco'

Many of the files are similarly redacted to remove nearly every little detail beyond the word UFO. 

Some in the mix merely mention the keywords 'UFO', 'UAP' or 'extraterrestrial' in the context of unrelated topics, offering little to no insight about the CIA's overall knowledge about those keywords. 

For example, one document entitled 'Hypervelocity Test Techniques Discussed' describes a French study of a force which could be used to deflect UFOs - defined in the document as 'undesired flying objects' - not unidentified ones. 

Another document joined the pile because it features a newspaper column about a Bosnian fugitive, in which the author mocks the Pentagon's failure to find the man despite 'communicating regularly with extraterrestrial beings'. 

One document entitled 'Hypervelocity Test Techniques Discussed' describes a French study of a force which could be used to deflect UFOs - defined in the document as 'undesired flying objects' - not unidentified ones

Another document joined the pile because it features a newspaper column about a Bosnian fugitive, in which the author mocks the Pentagon's failure to find the man despite 'communicating regularly with extraterrestrial beings'

'It was like pulling teeth': Greenewald recounts the 20 years he's spent fighting for access to CIA records on UFOs 

Black Vault's founder John Greenewald Jr (pictured) has spent the past two decades suing the CIA to release the records and then scanning the pages one by one

Greenewald began investigating the US government's research on UFOs when he was just 15 years old in 1996. 

He described his painstaking efforts to Motherboard on Monday, saying he filed countless Freedom of Information Act (FOIA) requests to unseal the records. 

'Around 20 years ago, I had fought for years to get additional UFO records released from the CIA,' Greenewald said.

'It was like pulling teeth. I went around and around with them to try and do so, finally achieving it.

'I received a large box, of a couple thousand pages, and I had to scan them in one page at a time.'

The dossier contains both the records that Greenewald requested and others that the CIA had already released publicly and compiled into a CD, which Black Vault purchased last year. 

In a blog post Greenewald noted that while the CIA claims it has released all of its UAP documents, there is no way to verify whether some documents may have been withheld.  

In a Twitter thread on Tuesday he explained how the records available on the CIA's website are incomplete, despite the agency 'giving the illusion' that everything is there. 

He posted screengrabs of a CIA site search which produced 415 results for UFO-related FOIA requests - compared to the 713 files on the Black Vault.  

In a Twitter thread on Tuesday Greenewald explained how the records available on the CIA's website are incomplete, despite the agency 'giving the illusion' that everything is there

Greenewald also emphasized how the CIA releases its records in a format that is far from user-friendly. 

'The CIA has made it incredibly difficult to use their records in a reasonable manner,' Greenewald told Motherboard.

'They offer a format that is very outdated (multi page .tif) and offer text file outputs, largely unusable, that I think they intend to have people use as a "search" tool. 

'In my opinion, this outdated format makes it very difficult for people to see the documents, and use them, for any research purpose. 

'Researchers and curious minds alike prefer simplicity and accessibility when they look at data dumps such as these.' 

Despite the inconvenience, Greenewald said thousands of people had already downloaded the archive on the first day it was posted on the Black Vault.  

He's offering the archive for free but set up a Patreon account for anyone who wants to donate money to support his past and future efforts to uncover CIA records. 

'Plain and simple, the public has a right to know,' Greenewald said. 

'When I began researching nearly 25 years ago at the age of 15, I knew there was something to this topic. Not because of viral internet hoaxes. Not because of back door meetings wherein I can’t tell you who, but I promise it was mind-blowing information. No, none of that. 

'It was simply because of the evidence that I got straight from the CIA. And the NSA. And the Air Force. And the DIA. I feel I am achieving what I set out to do. Easy access, to important material, for people to make up their own minds on what is going on.'

Greenewald (pictured) began investigating the US government's research on UFOs when he was just 15 years old in 1996. His Black Vault database is the result of countless different Freedom of Information Act (FOIA) requests

US intelligence faces six-month deadline to submit unclassified UFO report to Congress 

UFO detectives like Greenewald may soon have even more intel to sift through, with the upcoming deadline for US intelligence agencies to submit an unclassified report about 'unidentified aerial phenomena' to congressional intelligence and armed services committees.

The director of National Intelligence and the secretary of defense have just under six months to do so, after a stipulation in the 'committee comment' section of the Intelligence Authorization Act for Fiscal Year 2021 was included in the huge bill, according to CNN.

The Senate intelligence committee's directive said that the report should be unclassified, but it can contain a classified annex. Therefore, it is unlikely to reveal the discovery of extra-terrestrial life reaching earth.

It does, however, state that the report must contain detailed analysis of UFO data and intelligence collected by the Office of Naval Intelligence, the Unidentified Aerial Phenomena Task Force and the FBI. 

Detail of 'an interagency process for ensuring timely data collection and centralized analysis of all unidentified aerial phenomena reporting for the Federal Government' must be included, and it should designate an official responsible for that process.

A spokesperson for the Office of the Director of National Intelligence confirmed the requirement for the report to the fact-checking website Snopes. 

Navy pilots believe they spotted a UFO just off the coast in Jacksonville in 2015 (pictured)

In April last year, the Pentagon released three short videos - one from 2004 and two from 2015 - that showed 'unidentified aerial phenomena', which had earlier been confirmed to be real by the US Navy. 

The videos, recorded by infrared cameras, showed what appeared to be unidentified flying objects quickly moving across the sky.

In the background of two of the videos, service members can be heard reacting as they watch the objects, with one speculating it could be a drone.

In August, the Pentagon announced that it was setting up a task force to investigate the objects, but it is still unclear what the objects are or where they came from.

Both Pentagon officials and members of Congress have been concerned about the appearance of unidentified objects flying over US military bases, with some suggesting the objects in the video could be drones collecting intelligence.

In June last year, the Senate Intelligence Committee voted to have the Pentagon and intelligence community provide public analysis of such encounters.

This is not the first time the Pentagon has investigated aerial encounters with UFOs, having previously studied recordings of such incidents as part of a classified program launched by former Senator Harry Reid, that has since been shut down.

That program was launched in 2007 and closed in 2012, the Pentagon says, after it decided there were higher priority areas that required funding.

{ https://www.dailymail.co.uk/ }

18-01-2021 om 18:42 geschreven door peter  

CIA releases entire collection of UFO-related documents to truth-seeking website

By Brandon Specktor  

The 'Black Vault' documents cover everything from mysterious Russian explosions to top government officials being hand-delivered UFO intel.

U.S. Navy videos of alleged UFO sightings were declassified in 2020.

(Image: © U.S. Navy)

More than three decades' worth of government UFO records are now yours to download and peruse, thanks to the efforts of some intrepid truth-seekers.

The massive data dump includes more than 2,700 pages of UFO-related documents declassified by the CIA since the 1980s. (The U.S. government also calls them "unidentified aerial phenomena, or UAP). According to The Black Vault — an online repository of UFO-related documents operated by author John Greenwald Jr. — the documents were obtained through a long string of Freedom of Information Act (FOIA) requests filed over the last quarter century .

Over time, so many requests piled up that the CIA created a CD-ROM full of declassified documents, known as "The UFO collection." In mid-2020, Greenwald purchased the CD-ROM, and he recently finished uploading its contents as a series of searchable PDF files on his website. (You can find them at The Black Vault.)

• Related: Flying saucers to mind control: 22 declassified military & CIA secrets

The documents cover dozens of incidents, including the 1976 account of the government’s then-Assistant Deputy Director for Science & Technology being hand-delivered a mysterious piece of intelligence on a UFO, to the description of a mysterious midnight explosion in a small Russian town.

"Although the CIA claims this is their 'entire' [declassified] collection, there may be no way to entirely verify that," Greenwald wrote in a statement on The Black Vault website. "Research by The Black Vault will continue to see if there are additional documents still uncovered within the CIA's holdings."

The data dump arrives months before officials from the U.S. Department of Defense and intelligence agencies are due to appear before Congress and spill their guts on everything they know about UFOs, the New York Post reported. A provision attached to the nearly 5,600-page COVID-29 relief bill passed in late December 2020 requires the agencies, "to submit a report within 180 days … to the congressional intelligence and armed services committees on unidentified aerial phenomena."

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The provision follows a banner year for UFOs, when startling footage of an unidentified object darting around several U.S. Navy planes in 2004 and 2015 was finally declassified.

While the new data dump is significant, it's also just a drop in the bucket of The Black Vault's enormous archive. The website reportedly contains more than 2.2 million pages of UFO-related material in its archive, which Greenwald obtained through more than 10,000 FOIA requests. According to the Vault website, Greenwald filed his first FOIA request in 1996, when he was just 15 years old.

• Originally published on Live Science.

{ https://www.space.com/ }

18-01-2021 om 18:17 geschreven door peter  

Artist’s concept of a red giant star scorching a planet in orbit around it.

Image via ESO/ L. Calçada.

Earth exists thanks to our sun, having formed in orbit around it from a huge cloud of gas and dust in space, 4.5 billion years ago. Likewise, the sun will ruin Earth for living things, some 5 billion years from now. As the sun evolves, it’ll expand to become a red giant star and fry our planet to a cinder. What’s more, the death of the Earth will happen against a backdrop of change on a galactic scale. Our Milky Way galaxy and the Andromeda galaxy will be in the midst of a colossal collision that’ll forever alter our galactic home in space.

Our sun is a G-type star currently about halfway through its life cycle. This type of star is very stable for the majority of its life, quietly fusing hydrogen into helium in its interior for billions of years. One day, the hydrogen in the sun’s interior will be depleted. At that point, the inward pressure of gravity will win out over the outward pressure of the sun’s internal fusion, until the sun heats up enough to start fusing helium. At that point, the sun will balloon outward to become a red giant star.

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As the sun heats up and expands, its outer layers will envelop the innermost planets, Mercury and Venus. The outer edge of the sun will grow to reach roughly the orbit of Earth. Our planet’s water and atmosphere will boil away, leaving nothing behind but a charred, lifeless rock. Mars will take a while to heat up, but, eventually, Mars will be outside the habitable zone for humans, too. At that point, the moons of the outer planets – like Jupiter and Saturn – will be the only places left in our solar system for human colonies.

But these locations, too, will be only temporary fixes in the search for a new home.

As our sun expands into the red giant phase, the habitable zone around it will be pushed outward in the solar system.

Image via NASA/ Wendy Kenigsburg.

The red giant phase of the sun might continue for a billion years or so, but eventually the helium will run out, too. Then the sun will blow off an envelope of gas. Astronomers peering through telescopes in other star systems will see our sun as what we call a planetary nebula, a great shell of gas surrounding a dying star. Ultimately that shell will dissipate off into space, and what’s left of our sun will become a white dwarf star.

Earth’s astronomers can look outward into space to glimpse of Earth’s future. For example, 400 light-years away, a star known to astronomers as SDSS J1228+1040 is a white dwarf with its gas nebula funeral shroud, and within it astronomers have found the signature of a planetesimal still orbiting its home sun long after its calamitous death.

And what of the Milky Way galaxy itself, the great island of stars containing our Earth and sun? By the time our sun is ballooning into the red giant phase – long before it settles down as a white dwarf – the Milky Way itself will be undergoing a long process of inevitable collision with the giant spiral galaxy next-door, the Andromeda galaxy. The last humans on Earth – if any humans are left a couple of billion years from now – will see the Andromeda galaxy growing larger and brighter in the night sky. It’s currently barely visible to the unaided eye from a dark-sky site. But, a couple of billion years from now, the Andromeda galaxy will be a breathtaking, unmistakable whirl of stars easily visible in the night sky of any and all Earthly inhabitants.

As Andromeda and the Milky Way move closer to each other, the Andromeda galaxy’s great mass will begin to affect the stars in our Milky Way. Our galaxy is wide and flat, like a pancake. We on Earth currently see its stars on a dark August evening as a great hazy band across the sky. But as the gravity of Andromeda distorts their paths, the Milky Way’s stars will be strewn across our sky.

It may seem incredible, but stars within galaxies are so far apart that even when the two giant spirals collide there will be few fireworks from collisions between stars. However, gas clouds in the two galaxies will likely collide, forming vast conglomerations of new stars.

This series of illustrations shows the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy.

Image via NASA.

Ultimately, the Milky Way and Andromeda galaxies will settle down to form a new massive blob-shaped galaxy. By this point, Earth, our sun and the rest of our solar system might be in some entirely new location with respect to the galactic center. At present, Earth lies some 25,000 light-years from the center of the Milky Way. After Andromeda and the Milky Way merge, astronomers believe our home in space will have been ripped outward to a new galactic orbit some 100,000 light-years from the center of the new, large Andromeda-Milky Way combo galaxy. As theorist T.J. Cox of the Harvard-Smithsonian Center for Astrophysics said:

You could say that we’re being sent to a retirement home in the country.

And what will be the fate of humanity? That’s impossible to say. If it survives, humanity’s future will depend on our ability to travel away from our dying sun and set up camp elsewhere.

Fortunately, we have a few billion years to figure out how to accomplish this monumental task.

• Bottom line: What will be Earth’s fate? Earth is bound to become a dry, scorched rock, as our sun becomes a red giant star. What’s more, as the Milky Way and Andromeda galaxies collide, our sun and Earth (and the rest of our solar system) are expected to be hurled outward, away from the galactic center, to the outskirts of a new large galaxy created in the collision.

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{ https://earthsky.org/ }

18-01-2021 om 17:42 geschreven door peter  

Megalodons – the extinct giant sharks that lived in most of Earth’s oceans about 3 million years ago – gave birth to babies that were larger than adult humans, scientists say.

Megalodons are the biggest predatory sharks ever discovered.

Image via Shutterstock.com.

By Tom Fletcher, University of Leicester

Made famous by the 2018 blockbuster “The Meg,” the largest predatory shark ever discovered, the megalodon, is a bit of a mystery. We know it lived between 15 and 3.6 million years ago and it reached at least 45 feet (14 meters) in length, more than double the size of an adult great white. But learning any more about the giant shark requires a bit of detective work.

Because of its soft cartilaginous skeleton, only a few parts of the shark’s body are mineralized and preserved, including its teeth, skull and spine. This means the fossil record is very poor for this animal. Unsurprisingly, the predator’s 7-inch (17-cm) teeth have received a lot of attention from researchers. But in a newly published study, Professor Kenshu Shimada of DePaul University and colleagues sought clues elsewhere.

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By examining the spine of the now extinct megalodon, the team found it gave live birth to babies 6.5 feet (2 meters) long, larger than an average adult human. Exactly how the babies got so big was likely due to cannibalism, eating their unhatched siblings in the womb.

Secrets in the spine

Like humans, sharks have a spine made up of lots components called vertebrae, which grow as the animal gets older. The researchers measured the vertebra of a megalodon from the Miocene epoch, which lasted from 5 to 23 million years ago.

By comparing it to modern great white sharks, the team estimated that the megalodon it came from was around 30 feet (9 meters) long when it was alive, but they didn’t stop there. Sharks deposit rings of hard tissue on their vertebra each year, and like the trunk of a tree these can be used to estimate age.

To count these rings inside the scientists would have had to cut through the fossil, damaging it forever. The solution was to use detailed X-ray scanning to study the internal structures, without causing any harm to the priceless specimen, revealing this shark died when it was 46 years old.

Megalodon babies grew bigger than adult humans by eating their siblings in the womb.

Image via DePaul University/ Kenshu Shimada/ The Conversation.

Looking down through the layers, the team could see how large this vertebra was when the shark was born. Astonishingly, the size estimate at the first growth ring imply the shark was two meters (over 6 feet) when born, meaning it was larger than an average adult human at birth.

Some sharks lay eggs, while others give birth to live young. In most sharks, however, the eggs hatch inside the mother, where the young feed on the egg yolk and fluids that she secretes until they are born fully formed.

The enormous birth size estimate for this particular megalodon provides strong evidence that this species had the same reproductive mode, with a great deal of investment in a smaller number of huge offspring. The dark secret of the megalodon is that to achieve this size in the uterus, the developing young must have been eating a lot.

Eating their siblings

It is very likely, this new study argues, that the babies’ growth was fueled by cannibalism of their unhatched siblings, a sinister conveyor belt of high protein snacks for hungry pups.

It is unknown exactly how many megalodon embryos were produced. In basking sharks today, millions of eggs are created and sent to be fertilized. The hatched embryos begin to eat the surrounding eggs and in some cases, like the sand tiger shark, they eat other embryos too. Sharks can hold one or more pups in each of their two uteri, so it is likely at least two megalodons were born at a time.

This grim survival mechanism is not unique. All living sharks of the lamniform order, a group which includes great white, mako, and thresher sharks, use this strategy, which has existed for at least 70 million years.

This study also conservatively estimates the life expectancy of the species at 88-100 years old, using their spine data and well-established growth patterns of the teeth. This is in line with estimated ages for great white and whale sharks, only falling short of the record breaking 500-year-old Greenland sharks, known to live life in the slow lane of cold northern seas.

It seems the start of a megalodon’s life was a tale of two halves. They were protected by a wonderful mother sacrificing time and energy to her pups, while they wrought havoc in the womb.

• Tom Fletcher, Honorary Research Fellow in Palaeobiology, University of Leicester
• This article is republished from The Conversation under a Creative Commons license. Read the original article.
• Bottom line: A new study says the giant extinct megalodon shark’s enormous babies ate their siblings in the womb.

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18-01-2021 om 17:18 geschreven door peter  

2020’s sea ice minimum in the Arctic Ocean came on September 15. Arctic sea ice on that date covered an area of 1.44 million square miles (3.74 million square km). It was the 2nd-lowest Arctic sea ice extend since modern record keeping began. How do we know? Scientists at NASA and the National Snow and Ice Data Center (NSIDC) determined 2020’s sea ice minimum via an analysis of satellite data. 

See an animation of this image, from NASA’s Scientific Visualization Studio.

• Originally published by NASA Earth Observatory on January 6, 2021

Throughout 2020, the Arctic Ocean and surrounding seas endured several notable weather and climate events. In spring, a persistent heatwave over Siberia provoked the rapid melting of sea ice in the East Siberian and Laptev Seas. By the end of summer, Arctic Ocean ice cover melted back to the second-lowest minimum extent on record. In autumn, the annual freeze-up of sea ice got off to a late and sluggish start.

But any single month, season, or even year, is just a snapshot in time. The long view is more telling, and it is troubling.

Image via NASA Earth Observatory.

Forty years of satellite data show that 2020 was just the latest in a decades-long decline of Arctic sea ice. In a review of scientific literature, polar scientists Julienne Stroeve and Dirk Notz outlined some of these changes: In addition to shrinking ice cover, melting seasons are getting longer and sea ice is losing its longevity.

The longer melting seasons are the result of increasingly earlier starts to spring melting and ever-later starts to freeze-up in autumn. The map above shows trends in the onset of freeze-up from 1979 through 2019. Averaged across the entire Arctic Ocean, freeze-up is happening about a week later per decade. That equates to nearly one month later since the start of the satellite record in 1979.

The change is part of a cycle called the ice-albedo feedback. Open ocean water absorbs 90% of the sun’s energy that falls on it; bright sea ice reflects 80% of it. With greater areas of the Arctic Ocean exposed to solar energy early in the season, more heat can be absorbed, a pattern that reinforces melting. Until that heat escapes to the atmosphere, sea ice cannot not regrow.

Image via NASA Earth Observatory.

The chart above demonstrates another way the Arctic is changing: the average age of sea ice is becoming younger. At the start of the satellite record, much of the ice covering the Arctic Ocean was greater than four years old. Today, most of the ice covering the Arctic Ocean is “first-year ice,” ice that forms in winter and does not survive a single summer melt season. (After sea ice reaches its minimum extent each September, the remaining ice graduates to second-year status.)

Dominated by thin first-year ice, along with some older ice thinned by warm ocean water, the Arctic sea ice pack is becoming more fragile. In summer 2020, ships easily navigated the Northern Sea Route in ice-free waters, and even made it to the North Pole without much resistance.

Fortunately, summers are still not entirely ice-free. Stroeve, a researcher at University of Manitoba, said:

We’ve been hovering for some time around 4 million square kilometers [1.5 million square miles] of Arctic sea ice each summer.

She added that she intends to examine which conditions and processes could push sea ice to the next “precipitous drop,” when the extent of summer ice cover drops to a new benchmark of 3 million square kilometers (1 million square miles).

Ice floes in the Laptev Sea, which lies north of the Siberian coast. This part of the Arctic Ocean is usually a factory for new sea ice. But sea ice in the Laptev Sea reached a record low in 2020.

Image via Olenyok/ Shutterstock.

• Bottom line: Satellite data show that 2020 was just the latest in a 40-year-long decline of Arctic sea ice.
• Source: Changing state of Arctic sea ice across all seasons
• Via Earth Observatory

RELATED VIDEOS, selected and posted by peter2011

{ https://earthsky.org/ }

18-01-2021 om 16:43 geschreven door peter  

La fin de l'énigme de l'origine des trous noirs supermassifs avec la découverte du plus lointain quasar connu ? - Part I

Comment sont nés les trous noirs supermassifs, dont certains sont à l'origine des quasars, tapis au centre des galaxies ? Ils ne se seraient formés à partir d'étoiles géantes qui se seraient ensuite effondrées en trous noirs géants, germes des trous noirs supermassifs. C'est ce que suggère maintenant la découverte du plus lointain quasar connu à ce jour qui accrédite une autre hypothèse.

Il y a presque 50 ans, les astrophysiciens ont commencé à soupçonner qu'au cœur des grandes galaxies on trouverait des trous noirs supermassifs. La montée en puissance des moyens d'observation à toutes les longueurs d'onde depuis plus d'une décennie a confirmé cette intuition. Nous pensons aussi que derrière les prodigieux quasars, ces noyaux actifs de galaxies si brillants qu'on peut les voir à des milliards d'années-lumière de distance, se trouvent également ces mêmes astres compacts accrétant voracement de la matière dont on pense savoir maintenant qu'elle provient de courants de matière baryonique froids, canalisés par des filaments de matière noire.

Mais une énigme en a découlé. Ces trous noirs contiennent de plusieurs millions à plusieurs milliards de masses solaires, de sorte qu'ils ne peuvent résulter de l'effondrement d'étoiles ordinaires dont toutes les observations montrent qu'elles ne dépassent que rarement les 100 masses solaires.

Plusieurs mécanismes ont été proposés depuis environ un demi-siècle pour produire des germes de trous noirs supermassifs, germes dont les tailles vont croître avec les apports des courants froids et les collisions galactiques conduisant à la fusion des trous noirs géants que les grandes galaxies contiennent.

Trous noirs primordiaux, amas stellaires relativistes ou...

Ainsi, la naissance de l'Univers observable devait s'accompagner d'un plasma dense et turbulent de matière dont la densité fluctuait chaotiquement localement. Parfois, cette densité devait être suffisamment élevée pour s'opposer, par son champ de gravitation et tout aussi localement, à l'expansion du cosmos et à la pression du plasma de particules élémentaires. Des trous noirs primordiaux, de tailles très différentes, pouvaient donc prendre naissance en s'effondrant gravitationnellement. Malheureusement, ce scénario, bien que toujours autorisé par les observations, est devenu sévèrement contraint, et il n'est pas certain que ce soit vraiment ne serait-ce qu'une partie de la solution de l'énigme des trous noirs supermassifs.

Une autre hypothèse, moins connue, fait intervenir la naissance d'amas globulaires si denses que la théorie de la relativité générale est nécessaire pour rendre compte de leur comportement. Ces amas relativistes d'étoiles sont instables et peuvent s'effondrer gravitationnellement en trou noir. On se pose des questions sur eux depuis les années 1960, comme le montre l'exemple du prix Nobel de Physique Kip Thorne. À l'époque, certains pensaient même qu'ils pouvaient expliquer les quasars. En générant un important décalage vers le rouge du fait de leur champ de gravitation, on pouvait croire par erreur en appliquant la loi de Hubble-Lemaître qu'ils étaient très distants et donc très lumineux, ce qui pouvait expliquer la vraie nature des quasars. On sait aujourd'hui que ce n'est pas le cas et ces amas stellaires relativistes attendent encore un vrai contact avec les observations.

Troisième hypothèse, celle de l'existence tôt dans l'histoire du cosmos d'étoiles supermassives, elles aussi instables en raison d'effets relativistes. Comme Futura l'expliquait dans le précédent article ci-dessous, des simulations numériques crédibles font effectivement naître ce genre d'étoiles qui va rapidement donner naissance à des trous noirs intermédiaires entre les trous noirs stellaires classiques et les trous noirs supermassifs, contenant de l'ordre de 10.000 à 100.000 masses solaires.

Un trou noir 1.000 fois plus brillant que la Voie lactée

Aujourd'hui, une publication dans Astrophysical Journal Letters et que l'on peut trouver en accès libre sur arXiv semble en mesure de départager les scénarios avancés. Elle provient d'une équipe internationale d'astronomes qui annonce en tout premier lieu avoir établi un nouveau record de distance avec la découverte du plus lointain quasar connu à ce jour. Il a été débusqué dans les observations du réseau de radiotélescopes de l'Atacama Large Millimeter/submillimeter Array (Alma) au Chili.

Dans un catalogue, le quasar porte le nom de J0313-1806 et il est observé alors que le cosmos n'avait encore que 670 millions d'années environ. Or, la masse du trou noir derrière ce quasar, environ 1.000 fois plus brillant à lui seul que notre Voie lactée, est estimée à environ 1,6 milliard de fois celle du Soleil. Les observations d'Alma permettent d'estimer également que la galaxie hôte du quasar forme de nouvelles étoiles à une vitesse 200 fois supérieure à celle de notre Galaxie, et que la luminosité du quasar indique que le trou noir accrète et avale une quantité de matière équivalente à 25 Soleils chaque année.

Selon les chercheurs, un trou noir aussi massif, et né aussi tôt dans l'histoire du cosmos observable, serait donc apparu bien trop vite pour avoir démarré son existence suite à l'effondrement d'une étoile supermassive ou d'un amas stellaire relativiste.

Il ne resterait qu'une hypothèse en liste et ce n'est pas celle des trous noirs primordiaux bien qu'elle soit une cousine. Non, le trou noir derrière J0313-1806 se serait formé directement par l'effondrement d'un immense nuage d'hydrogène et d'hélium après le Big Bang.

Une coupe de l'intérieur d'une étoile supermassive d'environ 55.000 masses solaires débutant son explosion. Il s'agit d'une simulation montrant les courants de matière qui s'élèvent tels des panaches dans un volume dont le rayon est celui de l'orbite de la Terre.

© Ken Chen, UCSC 

Les trous noirs supermassifs sont-ils nés d'étoiles supermassives ?

Article de Laurent Sacco publié le 08/06/2020

Comment sont nés les trous noirs supermassifs, dont certains sont à l'origine des quasars, tapis au centre des galaxies ? De nouvelles simulations numériques sur le superordinateur japonais ATERUI II confortent le scénario où ils se seraient formés à partir d'étoiles géantes de quelque 10.000 masses solaires. Ces astres se seraient ensuite effondrés en trous noirs géants, germes des trous noirs supermassifs.

Le premier succès de la collaboration Event Horizon Telescope avec la première image d'un trou noir, en l'occurrence M87*, en sera sans nul doute suivi de bien d'autres, à commencer par une image d'un autre trou noir supermassif, celui au cœur de notre Voie lactée, Sgr A*. Mais cette réussite éclatante ne doit pas nous faire oublier que nous ne savons toujours pas vraiment comment sont nés les trous noirs, contenant de quelques millions à quelques milliards de masses solaires, que l'on observe depuis des décennies au centre des galaxies, qu'elles soient spirales ou elliptiques.

Il semble de plus en plus clair qu'ils sont nés à partir de trous noirs déjà bien plus massifs que les trous noirs stellaires, qui ne peuvent naître qu'à partir d'étoiles contenant une centaines de masses solaires tout au plus, et que la croissance de ces germes des trous noirs supermassifs se serait ensuite largement poursuivie, tout comme pour les galaxies, en raison de l'existence de courants froids de matière ordinaire canalisés par des filaments de matière noire. Mais quid de l'origine de ces germes eux-mêmes ?

Des nuages de matière géants qui s'effondrent directement en trou noir ?

Plusieurs hypothèses ont été avancées, par exemple, celle faisant intervenir des trous noirs cosmologiques primordiaux, vestiges de la phase à haute densité du Big Bang où de grandes quantités de matière pouvaient s'effondrer gravitationnellement en donnant directement ces trous noirs. Mais, il est aussi possible de faire intervenir des étoiles exotiques très massives faisant partie des toutes premières étoiles du cosmos observable, celles dites de Population III. Ces étoiles seraient nées dans les conditions particulières de l'Univers au moment des âges sombres, alors que la matière baryonique à l'origine de toutes les étoiles était constituée d'un mélange presque pur d'hydrogène, d'hélium et leurs isotopes, sans aucune trace d'éléments lourds comme le carbone, le silicium et le fer.

Cette différence est d'importance, depuis des milliards d'années, l'existence de poussières silicatées et carbonées est nécessaire pour permettre l'effondrement des nuages moléculaires et poussiéreux où naissent des pouponnières d'étoiles. En effet, en s'effondrant sous leur propre gravité, ces nuages s'échauffent et il apparait une pression qui stoppe l'effondrement, sauf si un agent dissipe une partie de la chaleur dans ces nuages, les conduisant à se refroidir. Au sortir du Big Bang, sans ces poussières, la formation des étoiles ne pouvait pas être la même, et de fait, on a également des problèmes pour faire naître des étoiles supermassives qui, après avoir explosé en supernovae, pourraient laisser des trous noirs géants contenant bien plus que quelques centaines de masses solaires, les germes des trous noirs supermassifs.

Il se trouve qu'une équipe d'astrophysiciens japonais de l'Université de Tohoku (Japon) vient d'apporter une nouvelle lumière sur la genèse possible de ces étoiles supermassives comme elle l'explique dans un article publié dans Monthly Notices of the Royal Astronomical Society mais que l'on peut aussi trouver en accès libre sur arXiv.

{ https://www.futura-sciences.com/sciences/ }

18-01-2021 om 14:52 geschreven door peter  

Des étoiles de 10.000 masses solaires

Sunmyon Chon et son collègue Kazuyuki Omukai ont ainsi utilisé le superordinateur ATERUI II pour effectuer des simulations 3D haute résolution qui étaient impossibles à faire auparavant et qui concernaient certaines variantes des scénarios envisagées pour la formation des étoiles supermassives. Rappelons que la théorie de ces objets nécessairement décrits au moyen de la théorie de la relativité générale d'Einstein a une longue histoire qui remonte au début des années 1960 avec les travaux de Hoyle, Chandrasekhar, Feynman et Zel’dovich pour ne citer qu'eux. Certains espéraient rendre compte avec elles des quasars nouvellement découverts. Par nature très lumineuses, elles devaient aussi subir un fort effet de décalage spectral vers le rouge à cause d'un fort champ de gravitation les faisant donc passer pour très lointaines en raison de la loi de Hubble-Lemaitre.

Il se trouve que les précédentes simulations de formations d'étoiles massives en faisaient naître trop peu à partir du gaz primordial du Big Bang. Ensuite, le début de l'enrichissement très rapide de ce gaz en éléments lourds inhibait leur formation. Les calculs montraient en effet que ces éléments lourds conduisaient des nuages atomiques d'hydrogène à se fragmenter en donnant des étoiles nettement moins massives.

Un extrait de la simulation des chercheurs japonais. Trois étoiles supermassives en noir sont bien visibles, les autres, en blanc et jaune, sont des étoiles ordinaires. L'échelle est donnée en unité astronomique (1 au valant 150 millions de km environ ).

© NAOJ 

Mais, avec les moyens de calculs modernes, les algorithmes des modèles qu'ont implémentés Chon et Omukai sur ATERUI II se sont mis à raconter un tout autre scénario. Les nuages atomiques enrichis en éléments lourds par les premières explosions de supernovae se fractionnaient en étoiles non-supermassives. Mais l'existence d'un fort flux de gaz en direction des régions les plus denses de ces nuages conduisent les jeunes étoiles vers ces régions où elles fusionnent en donnant des étoiles 10.000 fois plus massives que le Soleil !

Au final, il semble bien que ce scénario soit en mesure de rendre compte de la population de trous noirs supermassifs observée car le taux de leur formation est fortement augmenté. Mais il reste du travail à faire pour vraiment le confirmer. Ce qui est sûr, c'est qu'une nouvelle voie de recherche a été ouverte.

Trous noirs supermassifs : des étoiles supergéantes en seraient à l'origine - PART II

Article de Laurent Sacco publié le 13/03/2017

Comment sont nés les trous noirs supermassifs, dont certains sont à l'origine des quasars, tapis au centre des galaxies ? De nouvelles et récentes simulations numériques consolident une des hypothèses avancées : ils se seraient formés à partir d'étoiles géantes de quelque 100.000 masses solaires. L'étude des ondes gravitationnelles pourrait confirmer, ou pas, ce scénario.

Dès le début des années 1960, l'existence d'étoiles supermassives a été postulée pour expliquer les observations étonnantes concernant les quasars qui venaient tout juste de faire leur apparition en astrophysique (voir article ci-dessous). La luminosité intrinsèque de ces objets semblait difficile à admettre étant donné leur décalage spectral vers le rouge qui indiquait qu'ils étaient très lointains. Des quantités prodigieuses d'énergie devaient être libérées chaque seconde et il n'était pas possible d'en rendre compte à partir de réactions de fusion thermonucléaire. Il était alors plus confortable intellectuellement de supposer l'existence d'étoiles géantes proches de la Voie lactée, voire dans notre Galaxie, mais avec un champ de gravitation si élevé qu'il produisait l'important décalage observé. Cette hypothèse aida à la création de l'astrophysique relativiste car de telles étoiles devaient nécessairement être soumises à des effets non négligeables de la physique d'Einstein concernant le champ de gravitation.

Les quasars sont expliqués aujourd'hui en postulant l'existence de trous noirs supermassifs possédant entre plusieurs millions et plusieurs milliards de masses solaires. Mais cette hypothèse, qui éclaire de nombreuses observations, a conduit à une nouvelle énigme : comment ces objets se sont-ils formés ?

Des étoiles de 100.000 masses solaires comme graines de trous noirs

Les astrophysiciens et les cosmologistes explorent plusieurs pistes, dont un renouveau de l'hypothèse de l'existence des étoiles supermassives relativistes au début de l'histoire du cosmos observable. Nous n'en avons pour le moment observé aucune mais cela n'empêche pas les astrophysiciens numériciens de simuler leur formation et leur comportement sur ordinateur, à travers divers scénarios. L'un des derniers en date à ce sujet provient notamment de chercheurs du fameux Los Alamos National Laboratory, là où a été conçu et fabriqué la première bombe atomique.

Selon Joseph Smidt et ses collègues, comme ils l'expliquent dans un article déposé sur arXiv, les premiers trous noirs géants pourraient être nés de l'effondrement direct d'importants nuages d'hydrogène moléculaire et d'hélium ayant conduit à la formation, tout d'abord d'étoiles supermassives de... 100.000 masses solaires ! En s'effondrant gravitationnellement, elles vont ensuite donner naissance à des trous noirs qui vont accréter rapidement du gaz et devenir supermassifs, de l'ordre du milliard de masses solaires. Ils étaient déjà nombreux, un milliard d'années après le Big Bang.

D'autres scénarios sont possibles et il est probable qu'ils opèrent simultanément, rendant compte du spectre de masses des trous noirs supermassifs observés. Il est possible ainsi d'invoquer des fusions précoces de trous noirs massifs.

En ce qui concerne l'existence des étoiles supermassives, la mise en orbite en 2018 du télescope spatial James Webb pourrait contribuer à nous les révéler. À plus longue échéance, si l'on en croit des travaux réalisés l'année dernière par des membres de l'Institute for Computational Cosmology (ICC) de l'université Durham au sein du projet EAGLE et qui ont réalisé des simulations, ces différents scénarios conduisent à des émissions d'ondes gravitationnelles distinctes que l'on devrait pouvoir observer et mesurer avec eLISA, ce qui permettrait de les départager (voir la vidéo ci-dessus).

L'origine énigmatique des trous noirs supermassif - PART III

Article de Laurent Sacco publié le 11/11/2013

Une des énigmes de l'astrophysique et de la cosmologie concerne l'origine des trous noirs supermassifs occupant le cœur des galaxies. En faisant revivre une vieille hypothèse à l'aide de simulations numériques, un groupe d'astrophysiciens vient de proposer qu'ils se soient formés au sein d'étoiles supermassives dépassant 10.000 masses solaires. En s'effondrant, elles produiraient même deux trous noirs, ce qui est inédit, qui finiraient par fusionner.

Les trous noirs supermassifs contiennent de quelques millions à quelques milliards de masses solaires. On ne comprend pas vraiment comment ils se sont formés. On admet cependant qu'il y a généralement une relation entre la masse de ces trous noirs et la taille des galaxies qui les abritent. Cela suggère donc que ces astres compacts croissent de pair avec les galaxies. Problème : on ne sait pas très bien non plus comment ces dernières grandissent. On pensait que c'était essentiellement lors de fusions entre galaxies plus petites, mais il semble que des courants d'hydrogène froids soient aussi un mécanisme efficace et peut-être tout aussi important pour la formation des grandes galaxies. Lorsque deux galaxies fusionnent, il doit aussi en être de même pour leurs trous noirs supermassifs et ceux-ci doivent continuer à grandir en accrétant des nuages de gaz ou des courants de matière.

On pourrait croire que pendant le premier milliard d'années de l'univers observable, les trous noirs supermassifs n'étaient pas encore les monstres que l'on connaît et qu'ils ont grandi rapidement à partir de trous noirs beaucoup plus petits. Malheureusement, cette hypothèse résiste mal aux observations et aux calculs. Il faut qu'il ait existé assez tôt dans l'histoire du cosmos des graines de trous noirs supermassifs, de masses déjà très importantes. Des simulations conduites par des astrophysiciens du célèbre California Institute of Technology (Caltech) viennent de donner un nouvel éclairage sur ce problème, en faisant intervenir des astres relativistes théorisés pendant les années 1960 : les étoiles supermassives.

Une alternative à la théorie des quasars

En 1963, alors que l'on venait de découvrir les premiers quasars, Fred Hoyle et Williams Fowler refusaient de les considérer comme des objets aussi lointains que leurs décalages spectraux vers le rouge le laissaient entendre. Ils ont préféré postuler l'existence de ces étoiles plutôt que de commencer à admettre que la théorie du Big Bang de Gamow et Lemaître devait être juste.

Dans le cadre du modèle cosmologique standard de l'époque, dont Hoyle était l'un des créateurs, découvrir que dans le passé (en l'occurrence avec des objets très distants), l'univers était différent d'aujourd'hui, revenait à réfuter l'idée d'un univers éternel sans commencement, ni fin, ni évolution bien qu'en expansion. Avec des étoiles contenant plusieurs millions et même plusieurs milliards de fois la masse du Soleil, le champ de gravitation est si puissant qu'il produit un décalage spectral vers le rouge important. Les quasars n'avaient pas à être situés à des milliards d'années-lumière. Ils pouvaient même être dans la Voie lactée.

Feynman puis Chandrasekhar ne tardèrent pas à découvrir que les effets de la relativité générale rendaient des étoiles aussi massives très instables et qu'elles devaient s'effondrer en trou noir. Les années passant, avec la découverte du rayonnement fossile confirmant la théorie du Big Bang et le développement de la théorie des quasars, les étoiles supermassives ont été reléguées au placard.

Deux trous noirs dans une étoile supermassive

Des chercheurs viennent de les en sortir, comme le démontre l'article qu'ils ont déposé sur arxiv. Ils postulent la formation, par effondrement de nuage de gaz dans un halo de matière noire, d'étoiles ayant des masses comprises entre 10⁴ et 10⁶ masses solaires. En quelques millions d'années, en se refroidissant, ces astres amorcent leur effondrement gravitationnel et tournent de plus en plus vite, et ainsi s'aplatissent et deviennent plus compacts. Il se forme à l'intérieur deux concentrations de matière orbitant l'une autour de l'autre. Devenant plus denses, ces concentrations voient leurs températures grimper. Comme l'avaient déjà prédit en 1965 Igor Novikov et Yakov Zel’dovich, elles finissent par atteindre le seuil d'énergie correspondant à la création de paires d'électron et de positron. Cela rend ces concentrations très instables et elles s'effondrent rapidement pour donner deux trous noirs très massifs.

Ces deux objets vont rapidement se rapprocher l'un de l'autre, car ils perdent de l'énergie cinétique en rayonnant des ondes gravitationnelles. Ils vont finir par fusionner pour donner un trou noir qui a les bonnes propriétés pour grandir suffisamment vite dans le jeune cosmos, et rendre compte de l'existence des trous noirs supermassifs. Si les chercheurs ont raison, il doit exister dans le fond d'ondes gravitationnelles cosmologiques des traces de nombreuses fusions de trous noirs binaires issus de l'effondrement d'étoiles supermassives. Il se peut que l'on puisse les détecter un jour avec des instruments dans l'espace comme Lisa.

{ https://www.futura-sciences.com/sciences/ }

18-01-2021 om 14:50 geschreven door peter  

A Famous Harvard Professor Says an Extraterrestrial Visited in 2017, and We Can Expect More

When the first sight of intelligent alien life visits Earth from space, it won’t be a massive saucer hovering over New York. The chair of Harvard’s Department of Astronomy favors the possibility that it will be an extraterrestrial civilization’s trash. Avi Loeb believes he’s already found some of that trash.

The professor’s upcoming book, which will be out on January 26, lays out a compelling theory for why the object that recently wandered into our solar system was a piece of alien technology and not just another rock.  Dubbed as ‘Oumuamua,’ the space object measures only about a hundred yards long, but it was a major thing in the scientific community. It was first spotted in Hawaii through the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS).

Oumuamua traveled toward our solar system from star Vega, 25 light-years away from Earth, and intercepted our solar system’s orbital plane on September 6, 2017. It was the first-ever interstellar object detected inside our solar system. No crisp images were taken, but astronomers observed the thing for 11 days using their telescopes.

Scientists believed it was an ordinary comet, but Loeb suggested to have an open mind to another possibility. He explained that a cave dweller who has seen rocks all his life might have thought of a cellphone as just a shiny rock. Multiple strange properties about the space object helped Loeb conclude that it wasn’t a comet but discarded tech from an extraterrestrial civilization.

Firstly, Loeb points out Oumuamua’s dimensions. Scientists said the object was at least 5 to 10 times longer than it was wide, which resembled a cigar’s shape. No naturally occurring space body we’ve ever observed has looked like it or even close. The author also noticed the unusual brightness of the Oumuamua, which was at least ten times more reflective than known solar system comets or asteroids. He likens the object’s surface to that of shiny metal.

But the anomaly that really believed Loeb towards his alien hypothesis was the way the object moved. He says that it pushed away from the sun when it should have sped up toward the sun due to the sun’s gravitational force. Loeb writes that as the object moved away from the sun, it even accelerated slightly to a highly statistically significant extent. In other words, Oumuamua was being pushed by force besides the sun’s gravity.

The explanation seemed simple at first. The comets’ surface is warmed as they approach the sun, releasing once-frozen gases that act like a rocket engine. Those released materials form a comet’s distinctive tail, but scientists did not find any sign of gases or dust that might propel Oumuamua.

According to Loeb, skeptics are quick to assign natural origins of the object, and their explanations don’t stand up to the scrutiny of Oumuamua’s weird properties. Loeb believes that technology will soon find more space travelers, and the mystery of Oumuamua will only be settled if the same object is spotted and more thoroughly investigated with a probe.

RELATED VIDEOS, selected and posted by peter2011

{ https://www.latest-ufo-sightings.net/ }

18-01-2021 om 13:38 geschreven door peter  

UFOs: The Central Intelligence Agency (CIA) Collection

Below you will find a collection of CIA related UFO records. The Black Vault’s connection to the CIA in getting some of these UFO documents released goes back to 1996.

Originally, the CIA would only release about 1,000 pages that had been previously disclosed after a FOIA court case in the 1980s. They never addressed the records that were dated in the years after the case.

Photo of the CD-ROM, as received from the CIA by The Black Vault.

The Black Vault spent years fighting for them, and many were released in the late 1990s. However, over time, the CIA made a CD-ROM collection of UFO documents, which encompassed the original records, along with the ones that took years to fight for.

In an effort to make sure The Black Vault stayed up to date, in mid 2020, this CD-ROM was purchased to have one particular data dump available for all users of The Black Vault. You will find this below for download in its original state, along with a converted/searchable .pdf format. (Although the CIA claims this is their “entire” collection, there may be no way to entirely verify that. Research by The Black Vault will continue to see if there are additional documents still uncovered within the CIA’s holdings.)

• (Please note: Some media channels are reporting I filed 10,000 FOIA requests to get these documents. That is untrue. Over the years there were quite a few, but the reference is The Black Vault has filed 10,000 FOIA requests TOTAL to amass the 2.2 MILLION pages in this entire archive. Not just for the below documents. I’ve submitted corrections to Vice et al for that, but have heard no response yet.)

Entire CIA UFO Collection CD-ROM (2,780 Pages)

The links below offer two downloads. The contents of the original CD-ROM, as received, which is the multi-page .tif files (not searchable) with corresponding text files which are largely useless.

The second link is the converted records, wherein The Black Vault converted each .tif file to .pdf, and made it searchable. This is, by far, the more popular way of downloading and searching, but both are available for download.

 Original CIA UFO Collection CD-ROM Contents [149MB] – This is the entire collection, zipped up, with zero processing. This is in its original form.

 CIA UFO Collection CD-ROM Contents – Searchable .pdf Conversions – [342MB] – This .zip file contains all of the above files, however, they have been converted to searchable .pdf documents. Keep in mind, searchable .pdfs are NOT perfect. Many of these documents are poorly photocopied, so the computer can only “see” so much to convert for searching. However, through various tests, the search capability is MUCH better than the above CD contents with only .txt outputs.

Individual File Downloads (Searchable .pdfs)

Descriptions below are a work in progress. All documents are available, but all descriptions are not yet filled in.

	C05515622.pdf	477K	Two page memo from the CIA’s Domestic Collection Division regarding “UFO Research” – April 26, 1976
	C05515624.pdf	396K	One page document regarding “UFO Research/ORD Request for Additional Information.” The record talks about the work of an unknown individual, along with a system that may assist in the UFO research. The system is redacted. – June 25, 1976
	C05515625.pdf	385K	A one page, “Confidential” message to the HQ of the CIA’s Domestic Collection Division. It is regarding a UFO case, and UFO research, citing material that “should remain classified” but the person wanted the advice of “CIA UFO Experts.”
	C05515646.pdf	551K	A September 1976 record, heavily redacted, which talked about a UFO sighted in Morocco.
	C05515647.pdf	390K	A one page message regarding an unknown case number, seeking progress made. The message refers to the people at Wright Field (present day Wright Patterson Air Force Base) “holding their breaths awaiting advise.” – May 1957
	C05515648.pdf	425K	A one page message, wherein it references Dr. Leon Davidson, and his request seeking an updated on a “tape” being analyzed by Wright Field, likely Project Blue Book. Date unknown.
	C05515649.pdf	382K	A one page message updating on the Leon Davidson situation, and the fact Davidson was sent a letter response. – 1957.
	C05515650.pdf	420K	A 1957 document referencing Dr. Leon Davidson, and his request for an identification of a “Space Message.” The message appears they are frustrated that Davidson will not take the answer that the message was morse code.
	C05515651.pdf	417K	A 1957 document, also referring to Dr. Leon Davidson’s “space message.” Davidson continued to show frustration about the lack of answers he was receiving.
	C05515652.pdf	416K	A 1958 message concerning Leon Davidson, and the articles he was publishing about “flying saucers” and the CIA.
	C05515653.pdf	394K	A 1967 message regarding the film “UFO Fact or Fancy” – likely because the CIA was contacted for the production.
	C05515654.pdf	413K	A 1957 message regarding Dr. Leon Davidson, and his push for answers.
	C05515655.pdf	397K	1957 message concerning Dr. Leon Davidson, and the fact he would get a reply to his inquiries.
	C05515656.pdf	404K	December 1957 letter outline Dr. Leon Davidson’s persistence, and the recommendation he is now ignored.
	C05515657.pdf	406K	A 1958 document that displays the frustration about Dr. Leon Davidson, and the fact that the agency wants to no longer be involved with the matter.
	C05515658.pdf	414K	A 13 August 1957 intelligence report about Unidentified Flying Objects over Iran.
	C05515659.pdf	452K	A 22 October 1959 intelligence report about “Possible Unidentified Flying Object” in the Ukraine.
	C05515660.pdf	402K	A 9 March 1960 intelligence information report about “Rumored Unidentified Flying Objects in the Sary Ozek Region.”
	C05515661.pdf	427K	A 25 May 1962 document, which chronicles Unidentified Flying Objects in Buenos Aires, Argentina. This is utilizing information, as published by the local newspapers at the time of the event.
	C05515662.pdf	423K	A July 1965 document, outlining “Antarctic Flying Saucers” over Deception Island. This intelligence was gathered from the media.
	C05515663.pdf	468K	A 23 September 1977 document, which outlines “Unusual Natural Phenomenon observed in Karella.” For 10-12 minutes, an object described as a star, went over the city and shined down bright light and “very fine rays” which created an image of pouring rain.

Original Releases – Archived

The following are the original releases going back to about 1997. The above CD-ROM should include the records below as well, but they are archived here for reference.

 PDF File #1 (32 Megs) |  PDF File #2 (35 megs)

 Central Intelligence Agency releases multiple documents after a request was filed to the DIA in 2009 [65 Pages, 1.37MB] Released September of 2009 – These records prove the CIA is still collecting intelligence in regards to UFOs, and that material from just the past few years is considered a threat to our national security.

RELATED VIDEOS, selected and posted by peter2011

{ https://beforeitsnews.com/ }

18-01-2021 om 12:38 geschreven door peter  

UFO Caught Passing Light House On Island, Entering Ocean! South Carolina, Jan 2021, Video, UFO Sighting News.

Date of sighting: January 2021

Location of sighting: Hatteras Island, North Carolina, USA

 

The eyewitness Wes Snyder, a photographer by trade, caught something in his photos that appears to be a rectangle shaped alien craft as it was depending and probably entering the ocean. Since the earth is covered in 75% water, it makes sense that an aline base would be easiest to hide below the ocean floor, yes not on, but 5-6km below the floor. The light house is located on an island called Hatteras Island off North Carolina shore and this UFO was absolutely heading into the ocean. 

 

The object is large, like a 747 jet, but so incredibly fast that its seen only for a few seconds and only appears transparent. The transparentness may be due to a shield being raised to make it hidden, but often, camera filters can cut through such shields. Especially if the IR filter was previously removed from the camera to see true colors. 

Scott C. Waring - Taiwan 

 

Eyewitness states: 

{ https://www.ufosightingsdaily.com/ }

18-01-2021 om 11:32 geschreven door peter  

6 space missions to look forward to in 2021

From Martian rover landings to the launch of Hubble's "successor," here are some of the most exciting space missions pegged for next year.

{ https://www.techrepublic.com/ }

18-01-2021 om 01:56 geschreven door peter  

Here are some of the space missions to keep an eye out for in 2021.

The James Webb space telescope’s gold-coated mirror undergoing cryogenic testing. After many delays, the new space telescope – Hubble’s successor – is currently scheduled to launch on October 31.

Image via Ball Aerospace/ Flickr/ The Conversation.

By Ian Whittaker, Nottingham Trent University and Gareth Dorrian, University of Birmingham

Space exploration achieved several notable firsts in 2020 despite the Covid-19 pandemic, including commercial human spaceflight and returning samples of an asteroid to Earth.

This year is shaping up to be just as interesting. Here are some of the missions to keep an eye out for.

Artemis 1

Artemis 1 is to be the first flight of the NASA-led, international Artemis program, whose goal was (originally) to return astronauts to the moon by 2024. Artemis-1, which is still scheduled for launch late this year, will consist of an uncrewed Orion spacecraft which will be sent on a three-week flight around the moon. It will reach a maximum distance from Earth of 280,000 miles (450,000 km), the farthest into space that any spacecraft that can transport humans will have ever flown.

• EarthSky’s lunar calendar shows the moon phase for every day in 2021. Order yours before they’re gone!

Artemis 1 is designed to be launched into Earth orbit on the first NASA Space Launch System, which will be the most powerful rocket in operation. From Earth orbit, the Orion will be propelled onto a different path toward the moon by the rocket’s interim cryogenic propulsion stage. The Orion capsule will then travel to the moon under the power provided by a service module supplied by the European Space Agency (ESA).

The mission will provide engineers back on Earth with a chance to evaluate how the spacecraft performs in deep space and serve as a prelude to later crewed lunar missions. The launch of Artemis 1 is currently scheduled for late in 2021.

• Read more: Joe Biden will likely keep NASA’s Artemis program, but on a different timeline.

Mars missions

In February, Mars will receive a flotilla of terrestrial robotic guests from several countries. The United Arab Emirates’ Al Amal (Hope) spacecraft is the Arab world’s first interplanetary mission. It is scheduled to arrive in Mars orbit on February 9, where it will spend two years monitoring the Martian weather and disappearing atmosphere.

Arriving within a couple of weeks after Al Amal will be the China National Space Administration’s Tianwen-1, consisting of an orbiter and a surface rover. The spacecraft will enter Martian orbit for several months before deploying the rover to the surface. If it succeeds, China will become the third country to land anything on Mars. The mission has several objectives including mapping the mineral composition of the surface and searching for subsurface water deposits.

NASA’s Perseverance rover will land at Jezero Crater on February 18 and search for any signs of ancient life which may have been preserved in the clay deposits there. Critically, it will also store a cache of Martian surface samples on board as the first part in a highly ambitious international program to return samples of Mars to Earth.

Chandrayaan-3

In March 2021, the Indian Space Research Organization (ISRO) is planning to launch its third lunar mission: Chandrayaan-3. Chandrayaan-1 launched in 2008 and was one of the first major missions in the Indian space program. Comprising an orbiter and a surface penetrator probe, the mission was one of the first to confirm evidence of lunar water.

Unfortunately, contact with the satellite was lost less than a year later. Sadly, there was a similar mishap with its successor, Chandrayaan-2, which consisted of an orbiter, a lander (Vikram) and a lunar rover (Pragyan).

Artist’s concept of the the Chandrayaan-2 lunar mission from India.

Image via Raymond Cassel/ Shutterstock.

Chandrayaan-3 was announced a few months later. It will consist of only a lander and rover, as the previous mission’s orbiter is still functioning and providing data.

If all goes well the Chandrayaan-3 rover will touch down in the lunar south pole’s Aitken basin. It’s of particular interest as it is thought to host numerous deposits of subsurface water ice – a vital component for any future sustainable lunar habitation.

James Webb Space Telescope

The James Webb Space Telescope is the successor to the Hubble Space Telescope, but has had a rocky path to being launched. Initially planned for a 2007 launch, the Webb telescope is almost 14 years late and has cost roughly U.S. $10 billion (£7.4 billion) after apparent underestimates and overruns similar to those experienced by Hubble.

Whereas Hubble has provided some amazing views of the universe in visible and ultraviolet region of light, Webb is planning to focus observations in the infrared wavelength band. The reason for this is that when observing really distant objects there will probably be gas clouds in the way.

The galaxy NGC 2275 seen by Hubble.

Image via ESA/ Hubble/ NASA/ J. Lee and the PHANGS-HST Team.

These gas clouds block really small wavelengths of light, such as X-rays and ultraviolet light, while longer wavelengths like infrared, microwave and radio can get through more easily. So by observing in these longer wavelengths we should see more of the universe.

Webb also has a much bigger mirror of 21-foot (6.5-meter) diameter compared to Hubble’s 8-foot (2.4-meter) diameter mirror, essential for improving image resolution and seeing finer detail.

The primary mission of Webb is look at light from galaxies at the edge of the universe which can tell us about how the first stars, galaxies and planetary systems formed. Potentially this could include some information about the origin of life as well, as Webb is planning on imaging exoplanet atmospheres in high detail, searching for the building blocks of life. Do they exist on other planets, and if so, how did they get there?

We are also likely to be treated to some stunning images similar to those produced by Hubble. Webb is currently scheduled to launch on an Ariane 5 rocket on October 31.

• Ian Whittaker, Senior Lecturer in Physics, Nottingham Trent University and Gareth Dorrian, Post Doctoral Research Fellow in Space Science, University of Birmingham
• This article is republished from The Conversation under a Creative Commons license. Read the original article.
• Bottom line: 6 space missions set for 2021.

{ https://earthsky.org/ }

18-01-2021 om 01:37 geschreven door peter  

18-01-2021 om 01:20 geschreven door peter