Giant Mars Crater Shows Evidence of Ancient Lake

Giant Mars Crater Shows Evidence of Ancient Lake - New photos of a huge crater on Mars suggest water may lurk in crevices under the planet's surface, hinting that life might have once lived there, and raising the possibility that it may live there still, researchers say.

Future research looking into the chances of life on Mars could shed light on the origins of life on Earth, scientists added.

 

This view of layered rocks on the floor of McLaughlin Crater shows sedimentary rocks that contain spectroscopic evidence for minerals formed through interaction with water. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA'

The discovery came from a study of images by NASA's powerful Mars Reconnaissance Orbiter that revealed new evidence of a wet underground environment on the Red Planet. The images focused on the giant McLaughlin Crater, which is about 57 miles (92 kilometers) wide and so deep that underground water appears to have flowed into the crater at some point in the distant past.

Today, the crater is bone-dry but harbors clay minerals and other evidence that liquid water filled the area in the ancient past.

"Taken together, the observations in McLaughlin Crater provide the best evidence for carbonate forming within a lake environment instead of being washed into a crater from outside," study lead author Joseph Michalski, of the Planetary Science Institute in Tucson, Ariz., and London's Natural History Museum, said in a statement.

A wet Mars underground

Space agencies have deployed many missions to Mars over the decades to explore how habitable its surface may have been or is today. However, the Martian surface has been extremely cold, arid and chemically hostile to life as we know it for most of the history of Mars.

Instead of scanning the surface of Mars for life, scientists have suggested the most viable habitat for ancient simple life may have been in Martian water hidden underground.

On Earth, microbes up to 3 miles (5 km) or more underground make up perhaps half of all of the planet's living matter. Most of these organisms represent some of the most primitive kinds of microbes known, hinting that life may actually have started underground, or at least survived there during a series of devastating cosmic impacts known as the Late Heavy Bombardment that Earth and the rest of the inner solar system endured about 4.1 billion to 3.8 billion years ago.

Since Mars has less gravity — a surface gravity of a little more than one-third Earth's — its crust is less dense and more porous than that of our planet, which means that more water can leak underground, researchers said. Wherever there is liquid water on Earth, there is virtually always life, and microbes underground on Mars could be sustained by energy sources and chemical reactions similar to those that support deep-dwelling organisms on Earth.

"The deep crust has always been the most habitable place on Mars, and would be a wise place to search for evidence for organic processes in the future," Michalski told SPACE.com.

Subterranean Mars

While researchers currently have no way to drill deep underground on the Red Planet, they can nevertheless spot hints of what subterranean Mars is like by analyzing deep rocks exhumed by erosion, asteroid impacts or materials generated by underground fluids that have welled up to the surface.

Such upwelling would first occur in deep basins like McLaughlin Crater — as the lowest points on the surface, they would be where underground water reserves would most likely get exposed.

Scientists focused on McLaughlin Crater because it is one of the deepest craters on Mars. McLaughlin is about 1.3 miles (2.2 km) deep and is located in Mars' northern hemisphere.

The mineral composition of the floor of McLaughlin Crater suggests there was a lake made of upwelled groundwater there. Channels seen on the crater's eastern wall about 1,650 feet (500 meters) above its floor also hint at the former presence of a lake surface.

Michalski was actually originally trying to disprove the idea that groundwater breached the surface in many locations on Mars.

"Lo and behold, there was strong evidence for that process in this crater," he said. "Science is special because we are allowed to change our minds."

An ancient groundwater lake

The researchers estimate that a lake existed at McLaughlin Crater for an unknown duration between 3.7 billion and 4 billion years ago. "That makes the deposits as old as or older than the oldest rocks known to exist on Earth," Michalski said.

Mounds seen on the crater floor may have come from landslides or subsequent meteor impacts. These are important because they may have rapidly buried crater floor sediments.

"That is really cool because rapid burial is the scenario that is most advantageous for preservation of organic material, if any was present at that time," Michalski said.

Since life on Earth may have begun underground, learning more about any underground life that might have lived — or may still live — on Mars could shed light on the origins of life on Earth, researchers said.

"We should give serious consideration to exploring rocks representing subsurface environments in future missions," Michalski said. "That doesn't mean drilling, but instead exploring rocks formed from upwelling groundwater, or rocks naturally exhumed from the subsurface by meteor impact."

Michalski noted that some people may ask, "'Why do I hear about the detection of water or possibility of life on Mars all the time?' The answer is because Mars is habitable in more ways than we ever realized for many years, and we are finding water in many forms and environments on Mars — many more than we predicted for a long time."

The ingredients for life the researchers describe, "including energy sources, would have been more available early in Mars' history, but it doesn't take too much imagination to picture a scenario in which the subsurface is habitable today," Michalski said. He cautioned, however, "that is much different from saying that life is there today." ( space.com )

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Meteors May Inject Methane Into Alien Planet Atmospheres

Meteors May Inject Methane Into Alien Planet Atmospheres - Meteoroids slamming against the atmospheres of alien worlds could add organic gases that make them look inhabited by life even if they are not, researchers say.

In recent years, astronomers have detected hundreds of extrasolar planets. Many of these exoplanets lie within habitable zones, the zones around their stars warm enough for liquid water to persist on a planet's surface, raising hopes that life as we know it might live on these distant worlds.

Ground-based observatoriesand proposed-but-cancelled spacecraft such as the European Space Agency's Darwin project or NASA's Terrestrial Planet Finder could scan the atmospheres of exoplanets for signs of extraterrestrial life. Molecules each absorb specific types of light, resulting in patterns known as spectra that allow scientists to identify what the molecules are. Some chemicals or combinations of chemicals might be unique to life as we know it, and could thus serve as strong evidence of aliens.

One key gas astrobiologists looking for extraterrestrial life would concentrate on would be oxygen, since researchers often think this molecule is too chemically reactive to remain for long in the atmosphere of a rocky planet like Earth without organisms to continuously produce it. Another possibility would be methane, a colorless, odorless, flammable organic gas that microbes on Earth produce. Seeing both together in an exoplanet's atmosphere might be an especially significant sign of life, since they would both ordinarily remove each other from the atmosphere without something like life to constantly replenish them.

Methane on Mars

For more than 40 years, hints of methane have been seen on Mars, the first organic compound seen there. In the last decade, researchers have even suggested they have seen methane clouds that may have been forming over the Red Planet during the summer months in the last decade, raising the possibility of past or even extant organismsjust below the surface, although these findings remain hotly contested.

Although life or the byproducts of life are responsible for nearly all the methane found in Earth's atmosphere, it is not the only source of the gas. For instance, volcanism can produce methane, as can chemical reactions between water, carbon dioxide and minerals.

Another potential source of methane are carbon-rich micrometeoroids that generate the gas as the compounds in them burn up while entering a planet's atmosphere. Our solar system's main asteroid belt happens to be dominated by carbonaceous asteroids.

Although the number of micrometeoroids hitting Mars would not explain the levels of methane seen there, exoplanets in much dustier systems could potentially have enough methane produced in this manner to give off a false atmospheric signature of life.

"This could pose a problem, since the search for life on these exoplanets is dependent on remote observations such as spectroscopic analysis of their atmospheres, as had been used to detect the methane in the atmosphere of Mars," said researcher Richard Court, a planetary geologist at Imperial College London. "There is no chance of spacecraft physically visiting these exoplanets many light years away in the foreseeable future."

Past research suggests the only systems likely to possess debris disks dense enough to mimic a methane signature of life are either very young, or systems undergoing a massive set of collisions, such as was the case in our solar system during the Late Heavy Bombardment about 3.9 billion years ago, when millions of rocks cataclysmically blasted Earth and the rest of the inner solar system over a roughly 100-million-year period.

"Astronomers have been able to observe events analogous to the Late Heavy Bombardment occurring in other star systems," Court said.

Methane in meteorites?

To see how much methane carbonaceous micrometeoroids might generate on exoplanets, scientists calculated what an early, dustier version of our solar system was like. Currently Earth receives about 40,000 metric tons of micrometeoroids annually, while Mars sees about 12,000 metric tons. The researchers estimate that during the Late Heavy Bombardment, Earth and Mars saw about 1,000 to 10,000 times more.

During the entire Late Heavy Bombardment, Earth may have received about 33 million billion metric tons of micrometeoroids, while Mars received 1.7 million billion metric tons. This all may be enough for an exoplanet to have enough methane to make it look as if it might have life.

"These are the first people to address exoplanet atmospheres as they relate to micrometeoroids that produce methane upon atmospheric entry — people working with exoplanets hadn't thought of this before, and it's cool and something we should be aware of," said planetary scientist Sara Seager at the Massachusetts Institute of Technology, who did not take part in this study.

Court did caution that they assumed that the chemistry and abundance of the organic matter in micrometeorites falling to Earth is similar to that of micrometeorites in other star systems. "While some differences are inevitable, it is likely to be a reasonable assumption, because a search for evidence of life on planets outside the solar system will naturally seek to investigate a star system as similar as possible to ours," he said.

So far astronomers have detected a number of exoplanetary systems that may possess both planets and debris disks. One example may include Gliese 581 about 20 light-years from Earth, which has one and maybe two "super-Earths" — rocky planets larger than our own that can reach up to 10 times Earth's mass — around the red dwarf of the system's habitable zone.

"As we observe more star systems, it will be possible to apply our work to more extrasolar planets," Court said.

Court and his colleague Mark Sephton detailed their findings online Sept. 6 in the journal Planetary and Space Science. ( SPACE.com )

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Ingredients for Big Black Holes Detected in Milky Way's Core

Ingredients for Big Black Holes Detected in Milky Way's Core - Scientists investigated our galaxy's central molecular zone, which contains the most massive, densest, and most turbulent molecular clouds in the Milky Way. These surround the heart of our galaxy, which is suspected to be home to a supermassive black hole about 4 million times the mass of the sun.

The central molecular zones of galaxies crowd lots of gas close together, making them good places for stars to form. To learn more about these lively regions, scientists used radio telescopes to compile detailed maps of the temperature and density of clouds at the Milky Way's heart.

An artist's illustration of a newfound large star cluster near the center of the Milky Way that may be a breeding ground for intermediate black holes.

Now scientists have discovered four giant clumps of gas that appear to be the kinds of seeds intermediate-mass black holes arise from. These black holes hundreds to thousands of times the mass of the sun that are thought to in turn serve as the building blocks for the supermassive black holes found in the centers of galaxies.

The clumps are each about 30,000 light-years away. One of the masses contains the black hole suspected to exist at the heart of the Milky Way. This disk-shaped clump is about 50 light-years across "and revolves around the supermassive black hole at a very fast speed," said study lead author Tomoharu Oka, an astronomer at Keio University in Japan.

The other three clumps are expanding at very fast speeds of more than 223,000 miles per hour (360,000 kilometers per hour), making the researchers think supernova explosions were the cause of this growth, with the fastest blooming of these clumps growing as if 200 supernovas went off inside it. Since the age of this clump is only thought to be about 60,000 years old, which suggests supernovas happened there every 300 years.

Such a high rate of supernovas suggests that many young, massive stars are concentrated inside. The researchers estimate a massive star cluster more than 100,000 times the mass of the sun lurks within, as big as the largest star clusters in the Milky Way.

"No matter how large the star cluster is, it is very difficult to directly see the star cluster at thecenter of the Milky Way galaxy," Oka explained. "The huge amount of gas and dust lying between the solar system and the center of the Milky Way galaxy prevent not only visible light, but also infrared light, from reaching the earth. Moreover, innumerable stars in the bulge and disc of the Milky Way galaxy lie in the line of sight."

Huge star clusters at the center of the galaxy are where intermediate-mass black holes several hundred times the mass of the sun are expected to form.

"Many galaxies with central molecular zones may harbor such young massive clusters," Oka told SPACE.com.

"The new discovery is an important step toward unraveling the formation and growth mechanism of the supermassive black hole at the Milky Way galaxy's nucleus, which is a top-priority issue in galactic physics," he added in a statement.

It remains uncertain how many intermediate-mass black holes might lurk in the central molecular zones of galaxies, or at what rates they are created. "Further investigations of the central molecular zones of our galaxy and other galaxies will reveal them," Oka said. Specifically, the Atacama Large Millimeter/sub-millimeter Array (ALMA) of radio telescopes may detectintermediate-mass black holes, he added. ( SPACE.com )


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Asteroid Crashes Likely Gave Earth Its Water

Asteroid Crashes Likely Gave Earth Its Water - Asteroids from the inner solar system are the most likely source of the majority of Earth's water, a new study suggests.

The results contradict prevailing theories, which hold that most of our planet's water originated in the outer solar system and was delivered by comets or asteroids that coalesced beyond Jupiter's orbit, then migrated inward.

Artist’s impression of a 6-mile-wide asteroid striking the Earth. Scientists think approximately 70 of these dinosaur killer-sized or larger asteroids hit Earth between 3.8 and 1.8 billion years ago.

"Our results provide important new constraints for the origin of volatiles in the inner solar system, including the Earth," lead author Conel Alexander, of the Carnegie Institution of Washington, said in a statement. "And they have important implications for the current models of the formation and orbital evolution of the planets and smaller objects in our solar system."

Alexander and his colleagues analyzed samples from 86 carbonaceous chondrites. These primitive meteorites are thought to be key sources of the early Earth's volatile elements, such as hydrogen and nitrogen.

The team measured the abundance of different hydrogen, nitrogen and carbon isotopes in the chondrite samples. Isotopes are versions of an element that have different numbers of neutrons in their atomic nuclei. For example, the isotope deuterium — also known as "heavy hydrogen" — contains one neutron, while "normal" hydrogen has none.

The amount of deuterium in celestial bodies' water ice sheds light on where the objects formed in the solar system's early days. In general, bodies that took shape farther from the sun have relatively higher concentrations of deuterium, researchers said.

The 86 chondrite samples' deuterium content — which the team gleaned from clays, the remnants of water ice — suggest the meteorites' parent bodies formed relatively close to the sun, perhaps in the main asteroid belt between Mars and Jupiter.

Comets, by contrast, have much higher deuterium ratios. As a result, scientists think most of them were born in the solar system's frigid outer reaches.

The isotopic composition of the bulk Earth appears to be more consistent with chondrites than with comets, researchers said. There are many different types of chondrites, and no single group is a perfect match. So our planet probably accreted its water and other volatiles from a variety of chondrite parent asteroids, they added. ( space.com )


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Roswell, Other Famous UFO Claims Get a Fresh Look

Roswell, Other Famous UFO Claims Get a Fresh Look - Did a UFO really crash near Roswell, N.M., in 1947? What was that mysterious triangle of lights that hundreds of people spotted over Phoenix, Ariz., last fall? Are alleged alien abductees telling the truth? For a new series on the National Geographic Channel called "Chasing UFOs," a team of investigators visited UFO hotspots around the world and interviewed witnesses in an attempt to address some of history's most famous purported evidence that aliens have visited Earth.

We caught up with Ben McGee, a geoscientist and the lead field researcher on the UFO-chasing team, as well as its only skeptic, to get a taste of what he and his team discovered.

"I tried to help illustrate applying critical analysis to the range of alleged evidence," McGee told Life's Little Mysteries."The difference between UFO believers and astronomers is on the one hand you have people who find the data to support their hypothesis, and on the other you have the guys who attack their own hypothesis — who know there's a huge range of possible other explanations."

A military button found at a famous UFO crash site.

Military action

At Roswell, McGee and his team conducted a "recon-style survey" of the area around the alleged UFO crash site, testing for radiation and geomagnetic activity. They got lucky.

"We were doing some perimeter sweeps with metal detectors and got a hit," he said — it was a button from an Air Force member's coat.

"That jived with some of the alleged 'witness testimony' that said there was Air Force personnel sweeping the area after the crash to clean up debris," McGee said. But it also jives with what has been the military's story all along: that they were actually recovering debris from a crashed high-altitude surveillance balloon at the site rather than a flying saucer and its occupants. "Just because the military was there doesn't mean an alien was there," he said.

Triangle over Phoenix

The UFO chasers made another stop in the Southwest, in Phoenix, and spoke to people who saw a bizarre triangle of green lights moving slowly across the evening sky last September. The lights were definitely real — they were seen by many and recorded on video — but were they a UFO?

McGee, who does consulting work in the commercial space industry, has an alternative theory. He said a company called JP Aerospace is experimenting with balloon-based exploration, and is using enormous, silent V-shape craft that consist of two giant airships attached to a transfer station. Variations of the clever design are probably being tested by others, too, he said. "I would be shocked if the government wasn't using something similar, and that's a possible explanation for the Phoenix sighting."

Questionable accounts

The UFO chasers also interviewed many credible witnesses who believe Earth is being visited by aliens, including the moon-walking Apollo 14 astronaut Ed Mitchell. They also spoke to three women who claimed to have seen an injured alien creature near an alleged UFO crash site in Varginha, Brazil in 1996, and to a self-described alien abduction survivor in Colorado. One of McGee's fellow investigators on the show, James Fox, a ufologist and filmmaker, became convinced that the witnesses were telling the truth. McGee did not.

"James Fox is not a blind believer; he is very reasonable. But he tends to believe people if he doesn't see a reason for them to lie," McGee said. "But as a scientist, I know that human testimony is one of the least reliable types of data there is. It won't convince me of anything, especially if it's something extraordinary."

"Chasing UFOs" documents these and other exploits by McGee, Fox and fellow investigator Erin Ryder. The weekly series premieres on the National Geographic Channel Friday (June 29) at 9 p.m. ET/PT, with a second episode the first week at 10 p.m.

"People who are curious about UFOs are asking the right sorts of questions. They are curious about the possibility of life in the universe. This project has been an opportunity to engage with them," McGee said, "and to let people know there's no such thing as a bad question." ( LiveScience.com )

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Solar power station in Spain works at night

Solar power station in Spain works at night - A unique thermosolar power station in southern Spain can shrug off cloudy days: energy stored when the sun shines lets it produce electricity even during the night.

The Gemasolar station, up and running since last May, stands out in the plains of Andalusia.

The Torresol Energy Gemasolar plant in Fuentes de Andalucia near Seville. The unique thermosolar power station in southern Spain can shrug off cloudy days: energy stored when the sun shines lets it produce electricity even during the night. (AFP Photo/-)

From the road between Seville and Cordoba, one can see its central tower lit up like a beacon by 2,600 solar mirrors, each 120 square metres (1,290 square feet), that surround it in an immense 195-hectare (480-acre) circle.

"It is the first station in the world that works 24 hours a day, a solar power station that works day and night!" said Santago Arias, technical director of Torresol Energy, which runs the station.

The mechanism is "very easy to explain," he said: the panels reflect the suns rays on to the tower, transmitting energy at an intensity 1,000 times higher than that of the sun's rays reaching the earth.

Energy is stored in a vat filled with molten salts at a temperature of more than 500 degrees C (930 F). Those salts are used to produce steam to turn the turbines and produce electricity.

It is the station's capacity to store energy that makes Gemasolar so different because it allows the plant to transmit power during the night, relying on energy it has accumulated during the day.

"I use that energy as I see fit, and not as the sun dictates," Arias explained.

As a result, the plant produces 60 percent more energy than a station without storage capacity because it can work 6,400 hours a year compared to 1,200-2,000 hours for other solar power stations, he said.

"The amount of energy we produce a year is equal to the consumption of 30,000 Spanish households," Arias said, an annual saving of 30,000 tonnes of CO2.

Helped by generous state aid, renewable energies have enjoyed a boom in Spain, the world number two in solar energy and the biggest wind power producer in Europe, ahead of Germany.

For the Gemasolar solar product, foreign investors helped too: Torresol Energy is a joint venture between the Spanish engineering group Sener, which holds 60 percent, and Abu Dhabi-financed renewable energy firm Masdar.

"This type of station is expensive, not because of the raw material we use, which is free solar energy, but because of the enormous investment these plants require," Arias said.

The investment cost exceeds 200 million euros ($260 million).

But "the day when the business has repaid that money to the banks (in 18 years, he estimates), this station will become a 1,000-euro note printing machine!," he said, recalling that oil prices have soared from $28 a barrel in 2003 to nearly $130.

For now, the economic crisis has nevertheless cast a shadow over this kind of project: Spain is battling to slash its deficit as it slides into recession and has suspended aid to new renewable energy projects.

Andalusia, hard hit by the economic crisis with the country's highest unemployment rate at 31.23 percent, holds regional elections on March 25.

"We have three projects ready but stalled" because of the aid suspension, Arias said, admitting that in a difficult global economy the group has not managed to sell the Gemasolar techology abroad despite huge interest outside Spain. ( AFP )

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Was there a UFO in South Carolina? Exploding light ball caught on camera that shook homes and left residents calling 911

Was there a UFO in South Carolina? Exploding light ball caught on camera that shook homes and left residents calling 911 - Some residents of South Carolina received an initially terrifying awakening early Monday morning when their sky flashed bright blue and a large object was seen plummeting from the sky.

The unidentified flying object caught around Greenville county exploded in a few brief seconds causing an alarming boom that shook homes in several cities.

Over 30 emergency 911 calls were placed to at least one local police station while a number of fire fighters were dispatched before its mystery was solved.

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Startling: Over 30 emergency 911 calls were placed over the mysterious blue object caught falling from the sky

Explosion: Some firefighters were initially dispatched to the scene after hearing its explosion

Boom: The object's eventual crash shook some homes in the area

Identity: The object is believed to have been a bolide, a type of meteor or fireball

'It sounds like a typical bolide,' Dr Charles St Lucas of the Roper Mountain Science Center told Fox4 of what he believes was a meteor, albeit early of their next expected shower in late April.

'This one broke apart into three or four different pieces, glowed a bright blue white,' he said calling its spontaneity, 'delightful.'

With the sighting shortly before 2am, most residents didn't take it as coolly.

'I thought the aliens were coming,' one resident Cindie Stubbs told Fox4 with nervous excitement after witnessing the flash herself from above her home.

Morning fright: One startled witness, Cindie Stubbs, at first thought it could be extraterrestrial with it lighting up her backyard in the astonishingly bright blue glow at 2am

'I saw this big bright light that made the sand kind of almost sparkle it was so bright,' she said.

Bolides, according to the American Meteor Society, are a special type of fireball or astoundingly bright meteor.

They are known for exploding before their landfall with a bright flash, similar to the blue one seen around Greenville.

Dr St Lucas told GoUpState.com that the blue coloring indicates that it was composed of copper or copper chloride.

Being naturally occurring elements, it most likely wasn't falling 'space junk,' he reasons.

Injuries and damage from the sighting have not been reported. ( dailymail.co.uk )

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Human Survival Depends on Settling Space

Stephen Hawking : Human Survival Depends on Settling Space - Stephen Hawking, the famed astrophysicist, says we need to spread into outer space or else. If we don’t, he says, it will be difficult for the world “to avoid disaster in the next hundred years, let alone the next thousand or million.”

Hawking who has Lou Gehrig’s disease and speaks with the aid of a computer-synthesized voice, gave an interview to the Canadian Press to promote a new television series in the U.K. and Canada, “Brave New World With Stephen Hawking.” He answered questions by email, calling space exploration our most urgent mission.

“We are entering an increasingly dangerous period of our history,” he wrote in excerpts published by the Winnipeg Free Press and cited widely elsewhere.

Prof. Stephen Hawking. David Parry/Press Association/AP Photo

“Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill. But our genetic code still carries the selfish and aggressive instincts that were of survival advantage in the past. It will be difficult enough to avoid disaster in the next hundred years, let alone the next thousand or million.

“Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space.”

Hawking, now 69, has spoken on this theme before, though he warned in 2010 that it may be “too risky” to seek out intelligent aliens that he said almost certainly exist.

“If aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans,” he said at the time. “We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet.” ( abcnews.go.com )

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Seven Supernovae Found in Single Galaxy—A First

Seven Supernovae Found in Single Galaxy—A First - In a galaxy 250 million light-years from Earth, astronomers have spotted a record-breaking seven supernovae all found at the same time.

"As far as we know, only three supernovae in a single galaxy were found at once so far, which is already an impressive number," said study leader Fabien Batejat, a Ph.D. student at Chalmers University of Technology in Onsala, Sweden.

"But we can confirm seven supernovae [in a single galaxy], thanks to a 17-year monitoring of the radio sources in Arp 220."

The unprecedented find may offer a unique cosmic laboratory for studying galaxy evolution.

The galaxy Arp 220, where the seven supernovae were found.

The prodigious galaxy, known as Arp 220, is thought to have formed from the merger of two smaller galaxies and is well known to host a very intense burst of star formation, easily seen in visible wavelengths.

But the new data confirms that Arp 220 is also a very efficient factory for explosive star deaths, giving scientists a glimpse of how the earliest galaxies in the universe may have behaved.

Telescope Como Revealed Supernovae

Each of the supernovae found in Arp 220 spans less than a light-year, and at such a great distance, each radio signal covers an angle in the sky less than 0.5 milliarcseconds across, Batejat said.

"To give you an idea of how small this is, this size corresponds to what you would see if you would look into a straw of about 1,500 kilometers [932 miles] long," Batejat said.

"In order to see such small objects, we would need a telescope of 10,000 kilometers [6,214 miles] across, which is a bit less than the diameter of the Earth itself. But since we can't build such gigantic telescopes, we use interferometry to simulate them."

In astronomy, interferometry uses the combined power of an array of telescopes—rather than a single, huge telescope—to create high-resolution images that can probe deep into the universe.

Batejat's team used 57 of the largest radio telescopes on Earth, which are spread across two continents and five countries. The project included data from the European VLBI Network, the Very Long Baseline Array, the Green Bank Telescope, and the Arecibo Observatory.

The heart of Arp 220 is highly obscured by dust that can't be penetrated by visible wavelengths. But radio waves can travel through such a dense environment to reach telescopes on Earth.

Supernova Discovery Is "Something Amazing"

Ultimately the data revealed around 40 radio sources near the center of Arp 220. By watching how these sources changed over time in two different radio wavelengths, astronomers could tell that seven of the objects were stars that had exploded around the same time.

Astronomers estimate that our Milky Way galaxy sees only a single supernova every hundred years, on average, Batejat said.

But the highly active Arp 220, with its dynamic cycles of star birth and death, behaves more like how young galaxies probably did more than ten billion years ago.

"We hope this might lead to interesting discoveries on how stars formed [and died] in the early universe," Batejat said.

What's more, such relatively fresh supernovae "are rare, and they have short lives of a few decades maximum" before they settle into supernova remnants, he said. "So discovering seven such supernovae at once is something amazing." ( nationalgeographic.com )

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When stars collide! New study shows how gamma-ray bursts could end life on Earth

When stars collide! New study shows how gamma-ray bursts could end life on Earth - New research suggests the continuation of life on Earth depends on massive explosions on the other side of the galaxy.

The explosions, gamma-ray bursts thought to occur when two stars collide, can release tons of high-energy gamma-ray radiation into space.

Scientists believe they have already played a part in some the planet's extinctions.

Apocalyptic: Artist's illustration of a powerful gamma-ray burst, the most powerful type of explosion in the universe

They say the blasts could be contributing to the depletion of the Earth's ozone layer.

Brian Thomas, of Washburn University, in Topeka, Kansas, said: 'We find that a kind of gamma-ray burst — a short gamma-ray burst — is probably more significant than a longer gamma-ray burst.

'The duration is not as important as the amount of radiation.'

The research is being presented on Sunday, October 9, at the Geological Society of America's annual meeting in Minneapolis.

It is thought to be the first time scientists have connected the timing of these gamma-ray bursts to extinctions on Earth that can be dated through the fossil record.

Destructive power: For the first time scienists have connected extinctions on Earth and massive explosions on the other side of the galaxy

Livescience.com reports that there are two types of gamma-ray bursts: a longer, brighter burst and a 'short-hard' burst, which lasts less than a second but seems to give off more radiation than a longer burst.

If such a burst were to happen inside the Milky Way, its effects on Earth would be much longer lasting.

The short bursts may be caused by fender-benders between stars, such as dense neutron stars or black holes colliding.

The researchers were able to estimate that such collisions happen about once every 100 million years in a galaxy.

That means Earth would have been hit by several over the course of its history. ( dailymail.co.uk )

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Another flight of fancy for conspiracy theorists as 'UFO' is caught on camera off Cornish coast

Another flight of fancy for conspiracy theorists as 'UFO' is caught on camera off Cornish coast - Spotting a UFO is not the kind of sight-seeing you expect to find when you go on holiday.

But that is exactly what one man chanced upon without even realising it when he thought he was taking a picturesque photograph of the sea.

The witness had been taking a stroll in Black Head at Trenarren near St Austell, Cornwall at around 5pm on August 1, when he pulled out his camera to capture a snap of the sea.

Inexplicable: It seems that no-one can come up with a convincing explanation for this mysterious object

In a strange twist, it was not until he later downloaded the photograph from his digital camera onto his computer that he noticed the mysterious 'flying object' hovering above.

The photograph of the circular object has now been unveiled at the Cornwall UFO Research Group (CUFORG), which was founded by Dave Gillham in 1995.

He said: 'The person who took the photo never saw anything in the area while taking the photo.

'It was only when he got home and downloaded it onto his computer that he saw an object - a disc shaped craft, hovering just above the sea.

'There appear to be two trails of water beneath the object which looks as though they are falling from it in to the sea.

'It could be that the object has just emerged from the sea.'

Mr Gillham could not shed any further light on the origins of the object, which has left many scratching their heads for an explanation.

Other observers have a more straight forward answer - it is merely a seagull doing to the loo mid-flight.

A spokesman for the Royal Navy air base at nearby Culdrose confirmed that no military aircraft were in the area at the time.

He said: 'Culdrose did not have any aircraft airborne after 5pm on Monday August 1 so any helicopter in the St Austell area was not one of ours.

'As the airfield was closed until approximately 19.00 when the SAR was scrambled to an incident at Newquay the radar was not manned between 17.00 and 19.00.

'It is always possible of course that a civilian helicopter could have been in the vicinity of St Austell around 17.14.' ( dailymail.co.uk )

READ MORE - Another flight of fancy for conspiracy theorists as 'UFO' is caught on camera off Cornish coast

Planet Mercury Full of Strange Surprises, NASA Spacecraft Reveals

Planet Mercury Full of Strange Surprises, NASA Spacecraft Reveals - Mercury is not just hellishly hot but apparently covered in brimstone. A vast part of the planet is covered with dried lava – enough to bury the state of Texas under 4 miles of the stuff, scientists say.

These and other strange discoveries about Mercury were announced in seven papers released in the Sept. 30 issue of the journal Science, a trove of knowledge from NASA's Messenger probe, covering everything from odd landscape to the planet's magnetic core.

Messenger, which stands for "Mercury Surface, Space Environment, Geochemistry, and Ranging," marks humankind's first-ever orbiter around the solar system's smallest and innermost planet. It is only the second probe even to just visit, following the Mariner 10 flyby in the mid-1970s. Launched in 2004, the $446 million Messenger spacecraft began orbiting Mercury in March.

"Messenger is revealing that, contrary to many people's preconceptions, Mercury is a fascinating world with a complex history," study author Patrick Peplowski, a physicist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., told SPACE.com.

Volcanic history

For instance, high-resolutionimages of Mercury's surface reveal that epic lava flows helped create the planet's smooth northern plains. This once-molten rock filled craters more than a mile (1.6 kilometers) deep and covers 6 percent of Mercury's surface, an area equal to nearly 60 percent of the continental United States, explained planetary geoscientist James Head at Brown University.

Early in the planet's history, some 3.5 billion to 4 billion years ago, these gigantic volumes of lava poured from cracks in the surface as far as 125 miles (200 kilometers) outside the volcanic zone, flooding the surrounding, low-lying plains "like a bathtub," Head said.

Based on the way this lava apparently eroded the underlying surface, the researchers suggest it rushed out rapidly. "We can't say if it took 2.7 days or 15 years or any exact time from orbit, but it wasn't hundreds of millions of years," Head added.

Mercury's northern high latitudes had largely escaped view until now.

"When we flew by Mercury the first time with Mariner 10, we weren't really sure if volcanism caused these smooth plains," Head told SPACE.com. "Now we're in orbit with Messenger, we're up close and personal, just going around and around and really building up our picture of Mercury."

Head and his colleagues expect that other parts of Mercury also experienced volcanism. "This one deposit is so huge, volcanism has got to be important elsewhere," Head said.

Odd landforms

These images of Mercury's surface also revealed an odd feature — shallow, rimless hollows of irregular shapes. These hollows, ranging in diameter from tens of yards to a few miles, occur across Mercury and are commonly seen in clusters. Many of them appear relatively fresh.

Planetary scientist David Blewett at Johns Hopkins' Applied Physics Laboratory and his colleagues suspect these hollows were created when volatile materials — perhaps sulfur-bearing compounds — were liberated from the surface through some combination of heating, outgassing, explosive volcanism, micrometeoroid bombardment or solar radiation. This would suggest Mercury is loaded with higher levels of volatile materials than most scenarios of its formation predict.

"Analysis of the images and estimates of the rate at which the hollows may be growing leads to the exciting possibility that they are actively forming today," Blewett told SPACE.com. "It is exactly this kind of unexpected discovery that makes planetary exploration such an adventure."

Brimstone surface

The composition of Mercury's surface is substantially different from that of other terrestrial planets, according to Messenger's scans of the X-rays emanating from the planet. For instance, Mercury's surface possesses at least 10 times more sulfur, or brimstone, than Earth or the moon.

"These are the first measurements of the composition of the planet Mercury," study author Larry Nittler, a cosmochemist at the Carnegie Institution of Washington, told SPACE.com.

Altogether, this surface chemistry suggests the planet formed from material now seen in certain stony chondritic meteorites and cometary dust particles.

"It's thought that the terrestrial planets accreted from smaller bodies that were probably similar to or the same as the asteroids that give us chondritic meteorites as well as the dust that makes up comets," Nittler said. "Our work is showing that at some level, Mercury formed from a different mix of these building blocks than did the other terrestrial planets."

Measurements of gamma rays emanating from the planet's surface also support theories that Mercury originated from material comparable to that of stony chondritic meteorites.

These scans determined the abundances of the radioactive elements potassium, thorium and uranium. The measured ratio of potassium, a volatile element, to the non-volatile elements thorium and uranium revealed levels of volatile materials comparable to the other terrestrial planets.

"Our discovery of higher-than-expected volatiles on the surface is one of many results indicating that Mercury has more in common with Venus, Earth and Mars than was expected," Peplowski said. "These findings shed light on planetary formation processes in the early solar system, and by extension tell us about the formation of the other terrestrial planets as well. These results can even be extended to our understanding of extra-solar planets, particularly to large, rocky planets orbiting close to their host stars."

These findings also suggest that Mercury did not get as extremely hot as some models of the world's formation have suggested, because extreme heat would have baked out these volatiles. The findings also suggest Mercury's internal heat declined substantially since its formation, consistent with widespread volcanism about 3.8 billion years ago and isolated, limited volcanic activity ever since.

"As we continue to collect data from orbit, data from the Messenger Gamma-Ray Spectrometer will be used to measure global abundances of stable elements, like iron, silicon, and oxygen," Peplowski said. "We'll also start mapping the abundances of elements on the surface, which can tell us about regional geologic processes occurring on the surface."

Magnetic details revealed

Messenger also investigated the magnetic field of Mercury, the only terrestrial planet besides Earth to possess a global magnetic field. These fields come from the dynamos of these planets: electrically conducting fluids flowing in their liquid metallic cores.

"It is Earth's magnetosphere that keeps our atmosphere from being stripped away, and that makes it vital to the existence of life on our planet," said study co-author Jim Raines at the University of Michigan.

Magnetometer data found that Mercury's magnetic poles are lined up almost exactly with its rotation axis, off by no more than 3 degrees. At the same time, its magnetic equator is north of its geographical equator by about 300 miles (484 kilometers).

"The offset implies that the surface field in the north is three to four times stronger near the pole than it is near the southern magnetic pole," study author Brian Anderson, a space physicist at the Johns Hopkins University Applied Physics Laboratory, told SPACE.com. This in turn can affect how space radiation impacts the different hemispheres.

The magnetic field of Mercury is much weaker than Earth's. This is likely because Mercury's dynamo comes from just a thin shell of molten metal in its outer core.

"Now we have to understand how the circulation of the outer portion of the core, the part that is still molten, can generate a field that is both aligned with the spin axis of the planet and yet be so strongly skewed to the north," Anderson said. "My own hunch is that there are some subtle differences in the history of the dynamo in the north and south and that the thin shell dynamo at Mercury may allow the circulation in the north and south to evolve somewhat differently."

This weak magnetosphere also "provides very little protection of the planet from the solar wind," said study author Thomas Zurbuchen at the University of Michigan.

Earth's magnetosphere is strong enough to deflect most of the solar wind, but on Mercury, the solar wind apparently sandblasts the surface at the poles, knocking sodium particles off the planet, Zurbuchen and his colleagues said. Those particles become part of the "exosphere," the extraordinarily tenuous layer of molecules that makes up the closest thing Mercury has to an atmosphere.

Mercury, a magnetic weakling

Messenger also found that, unlike Earth and the other planets in the solar system with internal magnetic fields, Mercury is not surrounded by rings of charged particles. (Earth's rings are the Van Allen radiation belts.) Mercury's field is apparently too weak to support them. Instead, the spacecraft detected energetic bursts of electrons lasting from seconds to hours erupting from the planet.

"We have seen both proton and electron bursts in our own Earth's magnetosphere, but what really set these observations apart is the time scale and recurrent nature of these electron bursts at Mercury," study author George Ho, a space scientist at Johns Hopkins' Applied Physics Laboratory, told SPACE.com. "On Earth, such bursts happen irregularly and last for minutes, but at Mercury, those events last for few seconds, and we only detected electrons, not protons — still a puzzle to me."

On Earth, these bursts are due to the planet's magnetic field interacting with the interplanetary magnetic field. This might be going on at Mercury as well, or the bursts could be the result of Mercury's interaction with the solar wind. Ho said he hopes this data will help theorists better explain the bursts.

"All these findings are what exploration is all about," Head noted. "You can say you think you know what a place is like, but then you go there and orbit up close and personal, and you learn what's really going on. You challenge all your knowledge and come up with new ideas." ( SPACE.com )

READ MORE - Planet Mercury Full of Strange Surprises, NASA Spacecraft Reveals

The 7 Strangest Asteroids: Weird Space Rocks of the Solar System

The 7 Strangest Asteroids: Weird Space Rocks of the Solar System - This week, NASA's Dawn spacecraft will rendezvous with the asteroid Vesta. This will be our best look yet at an asteroid, and what the probe digs up could help scientists answer several questions about this and the hundreds of thousands of asteroids that populate the solar system.

Most asteroids, including Vesta, reside in the doughnut-like ring of the main asteroid belt that peppers the space between Mars and Jupiter. Other asteroids whirl in tight circles closer to the sun than the Earth, while a large number of them share planets' orbits. Not all asteroids are so happy to stay put, though: Some asteroids' orbits take them on planet-crossing swings through the inner solar system.

Given this variety of asteroids, some notably strange ones have popped up over our two centuries-plus of observations since the first asteroid, Ceres, was spotted in 1801.

In honor of Dawn's historic mission, which arrives at Vesta in the early morning hours of Saturday (July 17 EDT), here are seven of the solar system's strangest asteroids. (Note that space rocks out beyond the orbit of Jupiter, although somewhat asteroidal in nature, are classified as different bodies, and so we'll leave those alone for now.)

Ceres: A water-logged sphere?

The biggest asteroid by far is Ceres — which explains why it was discovered first — and it makes up about a third of the asteroid belt's mass. The object is so hefty that it's the only asteroid that has the gravitational strength to pull itself into a sphere.

On account of this roundness, Ceres is also considered a "dwarf planet," a designation it shares with four other objects in the solar system, including Pluto.

After scoping out Vesta, the Dawn spacecraft will journey on to Ceres, arriving in 2015. Once there, the spacecraft will gather data to help scientists learn more about Ceres' composition. The object is probably the "wettest" asteroid, with large stores of water in its interior as ice, though also possibly as a liquid layer beneath the surface.

Baptistina: The mother of the dinosaur killer

It's a name that, had they survived into modern day, dinosaurs (intelligent ones with language, at least) would curse: Baptistina.

Baptistina is the name of one of the youngest families of asteroids in the asteroid belt.
(Families of asteroids are swarms of objects that share orbital characteristics, and are often named after their most prominent member.)

According to computer models, Baptistina and its swarm were spawned some 160 million years ago by a smashup between a 37-mile-wide body (60 kilometer) body and another object about 106 miles (170 kilometers) in diameter. That cataclysm created hundreds of large objects, some of which then drifted into a collision course with Earth.

One or several of these rocky shards of shrapnel then plowed into our planet 65 million years ago and helped doom the dinosaurs. The impact gouged out the Chicxulub crater, now buried by the Yucatan peninsula and the Gulf of Mexico.

The 100-million-year Baptistina barrage did not spare the moon, either. A meteorite scooped out the giant Tycho crater about 109 million years ago.

Kleopatra: A metal dog bone — with moons!

Many asteroids, believe it or not, have a moon, and some even sport two satellites. Kleopatra has two moons, which were named Alexhelios and Cleoselene earlier this year. To boot, the metallic asteroid has an unusual dog-bone shape.

The asteroid is roughly 135 by 58 by 50 miles (217 by 94 by 81 kilometers) in length, height and width. Its moons Alexhelios and Cleoselene are, respectively, about 3 miles (5 kilometers) and 1.9 miles (3 kilometers) in diameter.

Hektor, the biggest Trojan

Like Kleopatra, Hektor is very elongated, with length and width dimensions of approximately 230 by 124 miles (370 by 200 kilometers). Hektor has a moon as well. Unlike Kleopatra, however, Hektor is not found in the main asteroid belt; instead, the dark, reddish body dominates as the biggest of Trojan asteroids stuck in Jupiter's orbit.

These rocks lurk in what are known as the L4 and L5 Lagrangian points — two of the five zones in an orbit where the gravity of two bodies (in this case, Jupiter and the Sun) balances out. L4 and L5 lie ahead and behind, respectively of Jupiter.

In reference to the combatants in the ancient poet Homer's epic Iliad, the L4 asteroids are known as the Greek camp and the L5 group is the Trojan camp. Although named for the Trojan hero, Hektor is actually in the Greek camp.

Themis: Icy giver of life?

Themis, a large main belt asteroid, stands out as the first and only asteroid known thus far to have ice on its surface.

In 2009, observations in infrared light confirmed the presence of this ice, as well as carbon-containing, or organic, molecules.

These characteristics make the icy asteroid Themis and similar bodies called main belt comets good candidates for having delivered water and carbon — some of the ingredients of life — to the surface of a young, hot, dried-out Earth some four billion years ago.

Toutatis: A tumbling dumbbell

Named after a Celtic god, the asteroid Toutatis is one of the oddest space rocks. Instead of rotating in an orderly fashion about an axis, the double-lobed object chaotically tumbles. This unpredictable movement partially derives from Toutatis being composed of two bodies barely in contact with each other and from the influences of both Earth and Jupiter's gravity.

Toutatis' path through the solar system has it sweep close to Earth, but because the asteroid's orbit is chaotic, its exact path — and how close it might come to us — centuries from now cannot be well predicted.

Like some other asteroids, Toutatis is said to be a like a "rubble pile" — fragments of rock that have gravitationally come back together after a collision, but left many gaps between them.

Apophis: The alleged Doomsday rock

Toutatis has made some close shaves to Earth, and passed within 1,000,000 miles (1.61 million kilometers) of Earth, or about four Moon distances, back in 2004. Yet some rocks have made notably closer passes, and the one that has most alarmed astronomers and the public alike is Apophis.

Discovered in 2004 and named after the Greek word for the evil Egyptian god of darkness, Apophis will return to the neighborhood in 2029. At the time, scientists calculated that its impacting Earth on that future pass were as high as 1 in 40, but subsequent measurements have now relegated that possibility to almost nil.

Panic peaked in December 2004, and Apophis achieved a ranking of 4 on the Torino scale, the 10-point scale that rates the risk of an object colliding with Earth (10 being an unquestioned apocalypse). Although Apophis is now deemed zero for its 2029 pass, it will zoom a mere 18,600 miles (30,000 kilometers) above Earth's surface.

A number of these other so-called Near Earth Objects, or NEOs, have yet to be cataloged. Yet some that have pose no threat, and benignly share Earth's orbit. At least four examples exist of asteroids that follow Earth in horseshoe-shaped orbits; a new one, designated 2010 SO16, was found earlier this year. ( Space.com )

READ MORE - The 7 Strangest Asteroids: Weird Space Rocks of the Solar System

UFOs seen in London skies

UFOs seen in London skies : viral video spotlight - A video purportedly showing a "UFO mothership" and a "fleet" of alien spacecraft has gone viral on YouTube on June 28, two days after it was uploaded.

UFO Mothership & Fleet Over London UK 24th June 2011 (credit alymc01) [HD] has as of 9:30GMT June 28 been viewed 710,431 times after being uploaded on June 26 and is ranked second on YouTube's "most watched today charts."

The video begins with shaky footage caused by what can be assumed to be the person behind the camera running down the street to where a group of people stand filming the sky on their mobiles. The camera then turns upwards, where three shining dots can be seen passing through the sky.

The circular dots then return several times before a similar larger shape appears, hovers for a short while then disappears at speed. In the background a man can be heard saying "There's a UFO up there."

The video was first uploaded June 24 by YouTube user alymc01, who despite being a member since 2007 appears to only have this video and a duplicate of it on his or her channel; the video that has gone viral is a re-post of that footage by user EllasVirgo.

The video has received some mainstream press coverage in addition to mentions on blogs specializing in UFOs. While no marketing company has yet come forward to claim responsibility for the footage, a number of similar videos have appeared on YouTube over the past few days, including UFOs Over London Friday 2011 - UFO fleet over Tower Bridge London 6/24/2011 and UFO June 2011, leading some to question if the videos are part of a viral promotional campaign. ( AFP )

READ MORE - UFOs seen in London skies