UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN

The dwarf planet Ceres keeps looking better and better as a possible home for alien life.

NASA's Dawn spacecraft has spotted organic molecules — the carbon-containing building blocks of life as we know it — on Ceres for the first time, a study published today (Feb. 16) in the journal Science reports.

And these organics appear to be native, likely forming on Ceres rather than arriving via asteroid or comet strikes, study team members said. [Photos: Dwarf Planet Ceres, the Solar System's Largest Asteroid

"Because Ceres is a dwarf planet that may still preserve internal heat from its formation period and may even contain a subsurface ocean, this opens the possibility that primitive life could have developed on Ceres itself," Michael Küppers, a planetary scientist based at the European Space Astronomy Centre just outside Madrid, said in an accompanying "News and Views" article in the same issue of Science.

"It joins Mars and several satellites of the giant planets in the list of locations in the solar system that may harbor life," added Küppers, who was not involved in the organics discovery.

Data gathered by NASA's Dawn spacecraft show a region around Ceres' Ernutet crater where organic concentrations have been discovered (labeled "a" through "f"). The color coding shows the strength of the organics' absorption band, with warmer colors indicating the highest concentrations.
**Credit: NASA/JPL-Caltech/UCLA/ASI/INAF/MPS/DLR/IDA**

Ceres finds keep rolling in

The $467 million Dawn mission launched in September 2007 to study Vesta and Ceres, the two largest objects in the main asteroid belt between Mars and Jupiter.

Dawn circled the 330-mile-wide (530 kilometers) Vesta from July 2011 through September 2012, when it departed for Ceres, which is 590 miles (950 km) across. Dawn arrived at the dwarf planet in March 2015, becoming the first spacecraft ever to orbit two different bodies beyond the Earth-moon system.

During its time at Ceres, Dawn has found bizarre bright spots on crater floors, discovered a likely ice volcano 2.5 miles (4 km) tall and helped scientists determine that water ice is common just beneath the surface, especially near the dwarf planet's poles.

The newly announced organics discovery adds to this list of achievements. The carbon-containing molecules — which Dawn spotted using its visible and infrared mapping spectrometer instrument — are concentrated in a 385-square-mile (1,000 square km) area near Ceres' 33-mile-wide (53 km) Ernutet crater, though there's also a much smaller patch about 250 miles (400 km) away, in a crater called Inamahari.

And there could be more such areas; the team surveyed only Ceres' middle latitudes, between 60 degrees north and 60 degrees south.

"We cannot exclude that there are other locations rich in organics not sampled by the survey, or below the detection limit," study lead author Maria Cristina De Sanctis, of the Institute for Space Astrophysics and Space Planetology in Rome, told Space.com via email.

Dawn's measurements aren't precise enough to nail down exactly what the newfound organics are, but their signatures are consistent with tar-like substances such as kerite and asphaltite, study team members said.

Organics probably native

"The organic-rich areas include carbonate and ammoniated species, which are clearly Ceres' endogenous material, making it unlikely that the organics arrived via an external impactor," co-author Simone Marchi, a senior research scientist at the Southwest Research Institute in Boulder, Colorado, said in a statement.

In addition, the intense heat generated by an asteroid or comet strike likely would have destroyed the organics, further suggesting that the molecules are native to Ceres, study team members said.

The organics might have formed via reactions involving hot water, De Sanctis and her colleagues said. Indeed, "Ceres shows clear signatures of pervasive hydrothermal activity and aqueous alteration," they wrote in the new study.

Such activity likely would have taken place underground. Dawn mission scientists aren't sure yet how organics generated in the interior could make it up to the surface and leave the signatures observed by the spacecraft.

"The geological and morphological settings of Ernutet are still under investigation with the high-resolution data acquired in the last months, and we do not have a definitive answer for why Ernutet is so special," De Sanctis said.

It's already clear, however, that Ceres is a complex and intriguing world — one that astrobiologists are getting more and more excited about.

"In some ways, it is very similar to Europa and Enceladus," De Sanctis said, referring to ocean-harboring moons of Jupiter and Saturn, respectively.

"We see compounds on the surface of Ceres like the ones detected in the plume of Enceladus," she added. "Ceres' surface can be considered warmer with respect to the Saturnian and Jovian satellites, due to [its] distance from the sun. However, we do not have evidence of a subsurface ocean now on Ceres, but there are hints of subsurface recent fluids."

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

Black Holes are Even Stranger Than You Can Imagine

An artist’s impression of a Sun-like star close to a rapidly spinning supermassive black hole, with a mass of about 100 million times the mass of our sun. Credit: ESA/Hubble, ESO, M. Kornmesser

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Our love of black holes continues to grow as our knowledge of these celestial bodies expands. The latest news is the discovery of a rare "middleweight" black hole, a relative newcomer to the black hole family.

We already knew that some black holes are just a few times the mass of our Sun, while others are more than a billion times as massive. But others with intermediate masses, such as the one 2,200 times the mass of our Sun recently discovered in the star cluster 47 Tucanae, are surprisingly elusive.

So what is it about black holes, these gravitational prisons that trap anything that gets too close to them, that captures the imagination of people of all ages and professions?

'Dark stars'

As far back as 1783, within the framework of Newtonian dynamics, the concept of "dark stars" with sufficiently high density that not even light can escape their gravitational pull had been advanced by the English philosopher and mathematician John Michell.

Almost immediately after Albert Einstein presented his theory of general relativity in 1915, which supplanted Newton's description of our Universe and revealed how space and time are intimately linked, fellow German Karl Schwarzschild and Dutchman Johannes Droste independently derived the new equations for a spherical or point mass.

Although at the time the issue was still something of a mathematical curiosity, over the ensuing quarter of a century nuclear physicists realised that sufficiently massive stars would collapse under their own weight to become these previously theorised black holes.

Their existence was eventually confirmed by astronomers using powerful telescopes, and more recently colliding black holes were the source of the gravitational waves detected with the LIGO instrumentation in the United States.

A dense object

The densities of such objects is mind-boggling. If our Sun were to become a black hole, it would need to collapse from its current size of 1.4 million km across to a diameter of less than 6km. Its average density within this "Schwarzschild radius" would be nearly 20 billion tonnes per cubic centimetre.

The increasing strength and pull of gravity as you get closer to a black hole can be dramatic.

On Earth, the strength of the gravitational pull holding you to its surface is roughly the same at your feet as it is at your head, which is a little bit farther away from the planet.

But near some black holes, the difference in gravitational pull from head to toe is so great that you would be pulled apart and stretched out on an atomic level, in a process referred to as spaghettification.

In 1958, the American physicist David Finkelstein was the first to realise the true nature of what has come to be called the "event horizon" of a black hole. He described this boundary around a black hole as the perfect unidirectional membrane.

It's an intangible surface encapsulating a sphere of no return. Once inside this sphere, the gravitational pull of the black hole is too great to escape – even for light.

In 1963, the New Zealand mathematician Roy Kerr solved the equations for the more realistic rotating black holes. These yielded closed time-like curves that permitted movement backwards through time.

While such strange solutions to the equations of general relativity first appeared in the 1949 work of Austrian-American logician Kurt Gödel, it is commonly thought that they must be a mathematical artefact yet to be explained away.

A video simulation of two black holes merging.

Black and white holes

In 1964, two Americans, the writer Ann Ewing and the theoretical physicist John Wheeler, introduced the term "black hole." Subsequently, in 1965, the Russian theoretical astrophysicist Igor Novikov introduced the term "white hole" to describe the hypothetical opposite of a black hole.

The argument was that if matter falls into a black hole, then perhaps it is spewed out into our universe from a white hole.

This idea is partly rooted in the mathematical concept known as an Einstein-Rosen bridge. Discovered (mathematically) in 1916 by the Austrian physicist Ludwig Flamm, and re-introduced in 1935 by Einstein and the American-Israeli physicist Nathan Rosen, it was later termed a "wormhole" by Wheeler.

In 1962, Wheeler and the American physicist Robert Fuller explained why such wormholes would be unstable for transporting even a single photon across the same universe.

Fact and fiction

Not surprisingly, the idea of entering a (black hole) portal and re-emerging somewhere else in the universe – in space and/or time – has spawned countless science fiction stories, including Doctor Who, Stargate, Fringe, Farscape and Disney's Black Hole.

Ongoing productions can simply claim that their characters are travelling to a different or a parallel universe to our own. While it appears to be mathematically feasible, there is of course no physical evidence to support the existences of such universes.

But this is not to say that time travel, at least in a limited sense, is not real. When travelling at great speed, or perhaps falling into a black hole, the passage of time does slow down relative to that experienced by stationary observers.

Clocks flown quickly around the world have demonstrated this, displaying time lags in accordance with Einstein's theory of special relativity.

The 2014 movie Interstellar played on this effect around a black hole, thereby creating a sense of travelling forward in time for astronaut Cooper (played by Matthew McConaughey).

Despite the strangely endearing name, the phrase "black hole" is perhaps somewhat misleading. It implies a hole in space-time through which matter will fall, as opposed to matter falling onto an incredibly dense object.

What actually exists within a black hole's event horizon is hotly debated. Attempts to understand this include the "fuzzball" picture from string theory, or descriptions of black holes in quantum gravity theories known as"spin foam networks" or "loop quantum gravity."

One thing that does seem certain is that black holes will continue to intrigue and fascinate us for some time yet."

Alister Graham, Professor of Astronomy, Swinburne University of Technology

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was published on Space.com.