Artist rendering of the system 30 Ari with its exoplanet and four stars. Excerpt from techtimes.com By Dianne Depra Researchers seeking to study the complexities of exoplanets with multiple stars have found a new system with four. Cal...
Excerpt from mashable.com In a world first, chemical engineers have taken a different look at a question astronomers and biologists have been pondering for decades: Does Saturn moon Titan host life?
Of course, Titan is way too hostile for life as we know it to eke out an existence — it is a frigid world awash with liquid methane and ethane and a noxious atmosphere devoid of any liquid water. But say if there is a different kind of biology, a life as we don't know it, thriving on the organic chemistry that is abundant on Titan's surface?
Normally, astrobiologists combine what we know about Earth's biosphere and astronomers zoom in on other stars containing exoplanets in the hope that some of those alien world have some similarities to Earth. By looking for small rocky exoplanets orbiting inside their star's habitable zones, we are basically looking for a "second Earth" where liquid water is at least possible. Where there's liquid water on Earth, there's inevitably life, so scientists seeking out alien life 'follow the water' in the hope of finding life with a similar terrestrial template on other planets.
Titan, however, does not fall into this category, it is about as un-Earth-like as you can get. So, chemical molecular dynamics expert Paulette Clancy and James Stevenson, a graduate student in chemical engineering, from Cornell University, Ithaca, New York, have looked at Titan in a different light and created a theoretical model of a methane-based, oxygen-free life form that could thrive in that environment.
There is no known template for this kind of life on Earth, but the researchers have studied what chemicals are in abundance on Titan and worked out how a very different kind of life could be sparked.
As a collaborator on the NASA/ESA Cassini-Huygens mission, Lunine, professor in the Physical Sciences in the College of Arts and Sciences’ Department of Astronomy, has been fascinated with the possibility of methane-based life existing on Titan for some time, so he joined forces with Clancy and Stevenson to see what this hypothetical life form might look like.
In their research published in the journal Science Advances on Feb. 27, Clancy and Stevenson focused on building a cell membrane "composed of small organic nitrogen compounds and capable of functioning in liquid methane temperatures of 292 degrees below zero (Fahrenheit; or 94 Kelvin)," writes a Cornell press release. On Earth, water-based molecules form phospholipid bilayer membranes that give cells structure, housing organic materials inside while remaining permeable. On Titan, liquid water isn't available to build these cell membranes.
"We're not biologists, and we're not astronomers, but we had the right tools," said Clancy, lead researcher of the study. "Perhaps it helped, because we didn't come in with any preconceptions about what should be in a membrane and what shouldn't. We just worked with the compounds that we knew were there and asked, 'If this was your palette, what can you make out of that?'"
The researchers were able to model the ideal cell that can do all the things that life can do (i.e. support metabolism and reproduction), but constructed it from nitrogen, carbon and hydrogen-based molecules that are known to exist in Titan's liquid methane seas. This chemical configuration gives this theoretical alien cell stability and flexibility in a similar manner to Earth life cells.
"The engineers named their theorized cell membrane an 'azotosome,' 'azote' being the French word for nitrogen. 'Liposome' comes from the Greek 'lipos' and 'soma' to mean 'lipid body;' by analogy, 'azotosome' means 'nitrogen body.'" — Cornell
"Ours is the first concrete blueprint of life not as we know it," said lead author Stevenson, who also said that he was inspired, in part, by Isaac Asimov, who wrote the 1962 essay "Not as We Know It" about non-water-based life.
Having identified a possible type of cell membrane chemistry that functions in the Titan environment as a cell on Earth might, the next step is to model how such a hypothetical type of biology would function on Titan. In the long run, we might also be able to model what kinds of observable indicators we should look for that might reveal that alien biology's presence.
That way, should a mission be eventually sent to Titan's seas, sampling the chemical compounds in the soup of organics may reveal a biology of a very alien nature.
Scientists have been trying to know if life could exist on Titan, the largest moon of Saturn. According to scientists, there are possibilities that life could survive amidst methane-based lakes of Titan. After conducting many studies, they have found signs of life on Titan, but the scientists also said that life will not be like life on earth. As per some scientific reports, Titan is the only object other than earth which has clear evidence of stable bodies of surface liquid. Like earth, the moon has mountains, islands, lakes and storms, but it doesn’t have oxygen, which is a major element to support life. It means that only oxygen-free and methane-based can exist on Titan. According to lead researcher Paulette Clancy, “We didn’t come in with any preconceptions about what should be in a membrane and what shouldn’t. We just worked with the compounds that, we knew were there and asked, ‘If this was your palette, what can you make out of that”.
Clancy said although they are not biologists or astronomers, they had the right tools to find life on Saturn’s largest moon. Adding to that, the researchers didn’t know what should be in a membrane and what should be not. They worked with compounds and found that life can exist on Titan, but would be very different from earth’s life, Clancy added. According to reports, the researchers had used a molecular dynamics method to know about Titan. They screened for suitable candidate compounds from methane for self-assembly into membrane-like structures. As per the researchers, the most promising compound they discovered was an acrylonitrile azotosome, which is present in the atmosphere of Titan. As per the researchers, acrylonitrile has shown good stability and flexibility similar to that of phospholipid membranes on Earth. It means that the Saturn largest has atmosphere and conditions to support life in a different way than earth. - See more at: http://perfscience.com/content/2141391-life-titan-would-be-different-earth#sthash.2Kqc3Ewf.dpuf
The machine NASA scientists used to zap out three components of our hereditary material from a chunk of ice.
Excerpt from cnet.com We know a whole lot about life on our planet, but one mystery persists: how it got here.
NASA scientists working at the Ames Astrochemistry Laboratory in California and the Goddard Space Flight Center in Maryland may have just found a clue to that mystery. They've determined that some of the chemical components of our DNA can be produced in the harsh crucible of space.
To reach their conclusion, they created a chunk of ice in their lab containing molecules known as pyrimidine. These molecules, which consist of carbon and nitrogen, form the core of three chemicals found in DNA and RNA, the genetic composition of all Earth-based life.
Pyrimidine is also found on meteorites, which prompted the researchers to explore how it reacts when frozen in water in space. So they put their chunk of ice in a machine that reproduces the vacuum of space, along with temperatures around -430°F and harsh radiation created by high-energy ultraviolet (UV) photons from a hydrogen lamp.
They found that not only could the pyrimidine molecules survive these brutal conditions, but the radiation actually morphed some of them into three chemical components found in DNA and RNA: uracil, cytosine and thymine.
"We are trying to address the mechanisms in space that are forming these molecules," Christopher Materese, a NASA researcher working on these experiments, said in a statement. "Considering what we produced in the laboratory, the chemistry of ice exposed to ultraviolet radiation may be an important linking step between what goes on in space and what fell to Earth early in its development." Added Scott Sandford, a space science researcher at Ames, "Our experiments suggest that once the Earth formed, many of the building blocks of life were likely present from the beginning. Since we are simulating universal astrophysical conditions, the same is likely wherever planets are formed."
While this research might help fill in a piece of the puzzle of our cosmic origins, another mystery remains. Scientists don't exactly know where meteoric pyrimidine comes from in the first place, although they theorize that it could arise when giant red stars die. And the search continues...
After six years of planetary observations, scientists at NASA say they have found convincing new evidence that ancient Mars had an ocean.
It was probably the size of the Arctic Ocean, larger than previously estimated, the researchers reported on Thursday. The body of water spread across the low-lying plain of the planet’s northern hemisphere for millions of years, they said.
If confirmed, the findings would add significantly to scientists’ understanding of the planet’s history and lend new weight to the view that ancient Mars had everything needed for life to emerge.
“The existence of a northern ocean has been debated for decades, but this is the first time we have such a strong collection of data from around the globe,” said Michael Mumma, principal investigator at NASA’s Goddard Center for Astrobiology and an author of the report, published in the journal Science. “Our results tell us there had to be a northern ocean.”
But other experts said the question was hardly resolved. The ocean remains “a hypothesis,” said Ashwin Vasavada, project scientist of the Curiosity rover mission at the Jet Propulsion Laboratory in Pasadena, Calif.
Dr. Mumma and Geronimo Villanueva, a planetary scientist at NASA, measured two slightly different forms of water in Mars’ atmosphere. One is the familiar H2O, which consists of two hydrogen atoms and one oxygen atom.
The other is a slightly “heavier” version of water, HDO, in which the nucleus of one hydrogen atom contains a neutron. The atom is called deuterium.
The two forms exist in predictable ratios on Earth, and both have been found in meteorites from Mars. A high level of heavier water today would indicate that there was once a lot more of the “lighter” water, somehow lost as the planet changed.
The scientists found eight times as much deuterium in the Martian atmosphere than is found in water on Earth. Dr. Villanueva said the findings “provide a solid estimate of how much water Mars once had by determining how much water was lost to space.”
He said the measurements pointed to an ancient Mars that had enough water to cover the planet to a depth of at least 137 meters, or about 450 feet. Except for assessments based on the size of the northern basin, this is the highest estimate of the amount of water on early Mars that scientists have ever made.
The water on Mars mostly would have pooled in the northern hemisphere, which lies one to three kilometers — 0.6 to 1.8 miles — below the bedrock surface of the south, the scientists said.
At one time, the researchers estimated, a northern ocean would have covered about 19 percent of the Martian surface. In comparison, the Atlantic Ocean covers about 17 percent of Earth’s surface.
The new findings come at a time when the possibility of a northern ocean on Mars has gained renewed attention.
The Curiosity rover measured lighter and heavier water molecules in the Gale Crater, and the data also indicated that Mars once had substantial amounts of water, although not as much as Dr. Mumma and Dr. Villanueva suggest.
“The more water was present — and especially if it was a large body of water that lasted for a longer period of time — the better the chances are for life to emerge and to be sustained,” said Paul Mahaffy, chief of the atmospheric experiments laboratory at the Goddard Space Flight Center.
Just last month, the science team running the Curiosity rover held its first formal discussion about the possibility of such an ocean and what it would have meant for the rest of Mars.
Scientists generally agree that lakes must have existed for millions of years in Gale Crater and elsewhere. But it is not clear how they were sustained and replenished.
“For open lakes to remain relatively stable for millions of years — it’s hard to figure how to do that without an ocean,” Dr. Vasavada said. “Unless there was a large body of water supplying humidity to the planet, the water in an open lake would quickly evaporate and be carried to the polar caps or frozen out.”
Yet climate modelers have had difficulty understanding how Mars could have been warm enough in its early days to keep water from freezing. Greenhouse gases could have made the planet much warmer at some point, but byproducts of those gases have yet to be found on the surface.
James Head, a professor of geological sciences at Brown University, said in an email that the new paper had “profound implications for the total volume of water” on ancient Mars.
But, he added, “climate models have great difficulty in reconstructing an early Mars with temperatures high enough to permit surface melting and liquid water.”
Also missing are clear signs of the topographic and geological features associated with large bodies of water on Earth, such as sea cliffs and shorelines.
Based on low-resolution images sent back by the Viking landers, the geologist Timothy Parker and his colleagues at the NASA Jet Propulsion Lab reported in 1989 the discovery of ancient shorelines. But later high-resolution images undermined their conclusions.
Still, Dr. Parker and his colleagues have kept looking for — and finding, they say — some visible signs of a northern ocean. The new data “certainly encourages me to do more,” he said in an interview.
Other researchers have also been looking for signs of an ancient ocean.
In 2013, Roman DiBiase, then a postdoctoral student at the California Institute of Technology, and Michael Lamb, an assistant professor of geology there, identified what might have been a system of channels on Mars that originated in the southern hemisphere and emptied steeply into the northern basin — perhaps, they said, water flowing through a delta to an ocean.
(Reuters) - Astronomers have found a star hurtling through the galaxy faster than any other, the result of being blasted away by the explosion of a massive partner star, researchers said on Thursday. The star, known as US 708, is traveling at about 746 miles (1,200 km) per second, fast enough to actually leave the Milky Way galaxy in about 25 million years, said astronomer Stephan Geier with Germany-based European Southern Observatory, which operates three telescopes in Chile.
"At that speed you could travel from Earth to the moon in five minutes," noted University of Hawaii astronomer Eugene Magnier. US 708 is not the first star astronomers have found that is moving fast enough to escape the galaxy, but it is the only one so far that appears to have been slingshot in a supernova explosion.
The 20 other stars discovered so far that are heading out of the galaxy likely got their impetus from coming too close to the supermassive black hole that lives at the center of the Milky Way, scientists report in an article in this week’s edition of the journal Science.
Before it was sent streaming across the galaxy, US 708 was once a cool giant star, but it was stripped of nearly all of its hydrogen by a closely orbiting partner. Scientists suspect it was this feeding that triggered the partner’s detonation.
If confirmed, these types of ejected stars may provide more insight into how supernova explosions occur. Since the explosions give off a fairly standard amount of radiation, scientists can calculate their distances by measuring how bright or dim they appear and determine how fast the universe is expanding.
Frank Drake, the founder of Search for Extraterrestrial Intelligence (SETI), at his home in Aptos, Calif. (Ramin Rahimian for The Washington Post)
Excerpt from washingtonpost.com It was near Green Bank, W.Va., in 1960 that a young radio astronomer named Frank Drake conducted the first extensive search for alien civilizations in deep space. He aimed the 85-foot dish of a radio telescope at two nearby, sun-like stars, tuning to a frequency he thought an alien civilization might use for interstellar communication.
But the stars had nothing to say.
So began SETI, the Search for Extraterrestrial Intelligence, a form of astronomical inquiry that has captured the imaginations of people around the planet but has so far failed to detect a single “hello.” Pick your explanation: They’re not there; they’re too far away; they’re insular and aloof; they’re zoned out on computer games; they’re watching us in mild bemusement and wondering when we’ll grow up.
Now some SETI researchers are pushing a more aggressive agenda: Instead of just listening, we would transmit messages, targeting newly discovered planets orbiting distant stars. Through “active SETI,” we’d boldly announce our presence and try to get the conversation started.
Naturally, this is controversial, because of . . . well, the Klingons. The bad aliens.
NASA discovers first Earth-size planet in habitable zone of another star
"NASA's Kepler Space Telescope has discovered the first validated Earth-size planet orbiting in the habitable zone of a distant star, an area where liquid water might exist on its surface. The planet, Kepler-186f, is ten percent larger in size than Earth and orbits its parent star, Kepler-186, every 130 days. The star, located about 500 light-years from Earth, is classified as an M1 dwarf and is half the size and mass of our sun." (NASA Ames Research Center)
“ETI’s reaction to a message from Earth cannot presently be known,” states a petition signed by 28 scientists, researchers and thought leaders, among them SpaceX founder Elon Musk. “We know nothing of ETI’s intentions and capabilities, and it is impossible to predict whether ETI will be benign or hostile.”
This objection is moot, however, according to the proponents of active SETI. They argue that even if there are unfriendlies out there, they already know about us. That’s because “I Love Lucy” and other TV and radio broadcasts are radiating from Earth at the speed of light. Aliens with advanced instruments could also detect our navigational radar beacons and would see that we’ve illuminated our cities.
“We have already sent signals into space that will alert the aliens to our presence with the transmissions and street lighting of the last 70 years,” Seth Shostak, an astronomer at the SETI Institute in California and a supporter of the more aggressive approach, has written. “These emissions cannot be recalled.”
That’s true only to a point, say the critics of active SETI. They argue that unintentional planetary leakage, such as “I Love Lucy,” is omnidirectional and faint, and much harder to detect than an intentional, narrowly focused signal transmitted at a known planet.
Astronomers have discovered a dust-filled ancient galaxy from the very early universe, which debunks earlier theories that earliest galaxies had no dust but gas. Astronomers from the University of Copenhagen used the Very Large Telescope’s X-shooter instrument along with the Atacama Large Millimeter/submillimeter Array and discovered a galaxy, named Galaxy A1689-zD1, which is an ancient galaxy and far from Earth. The astronomers stated that the galaxy which they were surprised to discover is far more evolved system than expected. It had a fraction of dust similar to a very mature galaxy, such as the Milky Way. Such dust is vital to life, because it helps form planets, complex molecules and normal stars.
According to the astronomers A1689-zD1 is only observable by virtue of its brightness being amplified more than nine times by a gravitational lens in the form of the spectacular galaxy cluster. Without the gravitational boost, the glow from this very faint galaxy would have been too weak to detect.
The astronomers stated that they are viewing A1689-zD1 when the Universe was only about 700 million years old, which is 5% of its present age. According to them, it is a relatively modest system — much less massive and luminous than many other objects that have been studied before at this stage in the early universe and hence a more typical example of a galaxy at that time.
A1689-zD1 is being observed as it was during the period of reionization, when the earliest stars brought with them a cosmic dawn, illuminating for the first time an immense and transparent universe and ending the extended stagnation of the Dark Ages. Expected to look like a newly formed system, the galaxy surprised the observers with its rich chemical complexity and abundance of interstellar dust.
Dust plays an extremely important role in the universe – both in the formation of planets and new stars.
Darach Watson, Associate Professor at Dark Cosmology Centre, University of Copenhagen, and the lead author of the study, said, “After confirming the galaxy’s distance using the VLT we realized it had previously been observed with ALMA. We didn’t expect to find much, but I can tell you we were all quite excited when we realized that not only had ALMA observed it, but that there was a clear detection. One of the main goals of the ALMA Observatory was to find galaxies in the early Universe from their cold gas and dust emissions — and here we had it!”
The researchers hope that future observations of a large number of distant galaxies could help unravel how frequently such evolved galaxies occur in this very early epoch of the history of the universe.
The military weather satellite that exploded in orbit last month apparently died of old age, U.S. Air Force officials say.
While investigators continue to study the dramatic Feb. 3 death of Defense Meteorological Satellite Program Flight 13 (DMSP-F13), the signs currently point not to a collision with a piece of space junk or other external cause but rather to an issue aboard the spacecraft, which launched in 1995.
"Basically, the spacecraft was 20 years old and experienced what appears to be a catastrophic event associated with a power system failure," Andy Roake, chief of the Current Operations Division at Air Force Space Command Public Affairs in Colorado Springs, told Space.com.
Investigators think that failure by itself probably blew apart DMSP-F13 — which occupied a sun-synchronous polar orbit about 500 miles (800 kilometers) above Earth — generating the cloud of debris that the Air Force's Joint Space Operations Center (JSpOC) has detected near the satellite. (To date, 43 pieces of debris have been identified.)
Indeed, Air Force officials have said that the military weather satellite explosion was preceded by a sudden spike in the power system's temperature, "followed by an unrecoverable loss of attitude control." It was first reported by SpaceNews, a Space.com partner, on Feb. 27.
DMSP-F13 launched in March 1995 and last year surpassed 100,000 orbits around Earth. The satellite contributed key data to a number of U.S. military operations overseas.
Studies may suggest methane-based organic processes ... but maybe not
New findings have roused a great deal of hoopla over the possibility of life on Saturn's moon Titan, which some news reports have further hyped up as hints of extraterrestrials.
However, scientists also caution that aliens might have nothing to do with these findings.
All this excitement is rooted in analyses of chemical data returned by NASA's Cassini spacecraft. One study suggested that hydrogen was flowing down through Titan's atmosphere and disappearing at the surface. Astrobiologist Chris McKay at NASA's Ames Research Center speculated that this could be a tantalizing hint that hydrogen is getting consumed by life.
"It's the obvious gas for life to consume on Titan, similar to the way we consume oxygen on Earth," McKay said.
Another study investigating hydrocarbons on Titan's surface found a lack of acetylene, a compound that could be consumed as food by life that relies on liquid methane instead of liquid water to live. "If these signs do turn out to be a sign of life, it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth," McKay said. However, NASA scientists caution that aliens might not be involved at all.
"Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed," said Mark Allen, principal investigator with the NASA Astrobiology Institute Titan team. "We have a lot of work to do to rule out possible non-biological explanations. It is more likely that a chemical process, without biology, can explain these results." McKay told Space.com that "both results are still preliminary."
To date, methane-based life forms are only speculative, with McKay proposing a set of conditions necessary for these kinds of organisms on Titan in 2005. Scientists have not yet detected this form of life anywhere, although there are liquid-water-based microbes on Earth that thrive on methane or produce it as a waste product.
On Titan, where temperatures are around minus-290 degrees Fahrenheit (-179 degrees Celsius), any organisms would have to use a substance that is liquid as its medium for living processes. Water itself cannot do, because it is frozen solid on Titan's surface. The list of liquid candidates is very short — liquid methane and related molecules such as ethane. Previous studies have found Titan to have lakes of liquid methane.
Missing hydrogen? The dearth of hydrogen Cassini detected is consistent with conditions that could produce methane-based life, but do not conclusively prove its existence, cautioned researcher Darrell Strobel, a Cassini interdisciplinary scientist based at Johns Hopkins University in Baltimore. Strobel wrote the paper on hydrogen appearing online in the journal Icarus.
Strobel looked at densities of hydrogen in different parts of the atmosphere and at the surface. Previous models from scientists had predicted that hydrogen molecules, a byproduct of ultraviolet sunlight breaking apart acetylene and methane molecules in the upper atmosphere, should be distributed fairly evenly throughout the atmospheric layers.
Strobel's computer simulations suggest a hydrogen flow down to the surface at a rate of about 10,000 trillion trillion molecules per second.
"It's as if you have a hose and you're squirting hydrogen onto the ground, but it's disappearing," Strobel said. "I didn't expect this result, because molecular hydrogen is extremely chemically inert in the atmosphere, very light and buoyant. It should 'float' to the top of the atmosphere and escape."
Strobel said it is not likely that hydrogen is being stored in a cave or underground space on Titan. An unknown mineral could be acting as a catalyst on Titan's surface to help convert hydrogen molecules and acetylene back to methane.
Although Allen commended Strobel, he noted "a more sophisticated model might be needed to look into what the flow of hydrogen is."
Consumed acetylene? Scientists had expected the sun's interactions with chemicals in the atmosphere to produce acetylene that falls down to coat Titan's surface. But when Cassini mapped hydrocarbons on Titan's surface, it detected no acetylene on the surface, according to findings appearing online in the Journal of Geophysical Research.
Instead of alien life on Titan, Allen said one possibility is that sunlight or cosmic rays are transforming the acetylene in icy aerosols in the atmosphere into more complex molecules that would fall to the ground with no acetylene signature.
In addition, Cassini detected an absence of water ice on Titan's surface, but loads of benzene and another as-yet-unidentified material, which appears to be an organic compound. The researchers said that a film of organic compounds is covering the water ice that makes up Titan's bedrock. This layer of hydrocarbons is at least a few millimeters to centimeters thick, but possibly much deeper in some places.
"Titan's atmospheric chemistry is cranking out organic compounds that rain down on the surface so fast that even as streams of liquid methane and ethane at the surface wash the organics off, the ice gets quickly covered again," said Roger Clark, a Cassini team scientist based at the U.S. Geological Survey in Denver. "All that implies Titan is a dynamic place where organic chemistry is happening now."
All this speculation "is jumping the gun, in my opinion," Allen said.
"Typically in the search for the existence of life, one looks for the presence of evidence -- say, the methane seen in the atmosphere of Mars, which can't be made by normal photochemical processes," Allen added. "Here we're talking about absence of evidence rather than presence of evidence — missing hydrogen and acetylene — and oftentimes there are many non-life processes that can explain why things are missing."
These findings are "still a long way from evidence of life," McKay said. "But it could be interesting."
Excerpt from space.com by Mike Wall Is it time to take the search for intelligent aliens to the next level? For more than half a century, scientists have been scanning the heavens for signals generated by intelligent alien life. They haven't found anything conclusive yet, so some researchers are advocating adding an element called "active SETI" (search for extraterrestrial intelligence) — not just listening, but also beaming out transmissions of our own designed to catch aliens' eyes.
Active SETI "may just be the approach that lets us make contact with life beyond Earth," Douglas Vakoch, director of interstellar message composition at the SETI Institute in Mountain View, California, said earlier this month during a panel discussion at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Jose.
Vakoch envisions using big radio dishes such as the Arecibo Observatory in Puerto Rico to blast powerful, information-laden transmissions at nearby stars, in a series of relatively cheap, small-scale projects.
"Whenever any of the planetary radar folks are doing their asteroid studies, and they have an extra half an hour before or after, there's always a target star readily available that they can shift to without a lot of extra slough time," he said.
The content of any potential active SETI message is a subject of considerable debate. If it were up to astronomer Seth Shostak, Vakoch's SETI Institute colleague, we'd beam the entire Internet out into space.
"It's like sending a lot of hieroglyphics to the 19th century — they [aliens] can figure it out based on the redundancy," Shostak said during the AAAS discussion. "So, I think in terms of messages, we should send everything."
While active SETI could help make humanity's presence known to extrasolar civilizations, the strategy could also aid the more traditional "passive" search for alien intelligence, Shostak added. "If you're going to run SETI experiments, where you're trying to listen for a putative alien broadcast, it may be very instructive to have to construct a transmitting project," he said. "Because now, you walk a mile in the Klingons' shoes, assuming they have them."
Cause for concern?
But active SETI is a controversial topic. Humanity has been a truly technological civilization for only a few generations; we're less than 60 years removed from launching our first satellite to Earth orbit, for example. So the chances are that any extraterrestrials who pick up our signals would be far more advanced than we are.
This likelihood makes some researchers nervous, including famed theoretical physicist Stephen Hawking.
"Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they could reach," Hawking said in 2010 on an episode of "Into the Universe with Stephen Hawking," a TV show that aired on the Discovery Channel. "If so, it makes sense for them to exploit each new planet for material to build more spaceships so they could move on. Who knows what the limits would be?"
Astrophysicist and science fiction author David Brin voiced similar concerns during the AAAS event, saying there's no reason to assume that intelligent aliens would be altruistic.
"This is an area in which discussion is called for," Brin said. "What are the motivations of species that they might carry with them into their advanced forms, that might color their cultures?"
Brin stressed that active SETI shouldn't be done in a piecemeal, ad hoc fashion by small groups of astronomers.
"This is something that should be discussed worldwide, and it should involve our peers in many other specialties, such as history," he said. "The historians would tell us, 'Well, gee, we have some examples of first-contact scenarios between advanced technological civilizations and not-so-advanced technological civilizations.' Gee, how did all of those turn out? Even when they were handled with goodwill, there was still pain."
Out there already
Vakoch and Shostak agreed that international discussion and cooperation are desirable. But Shostak said that achieving any kind of consensus on the topic of active SETI may be difficult. For example, what if polling reveals that 60 percent of people on Earth are in favor of the strategy, while 40 percent are opposed?
"Do we then have license to go ahead and transmit?" Shostak said. "That's the problem, I think, with this whole 'let's have some international discussion' [idea], because I don't know what the decision metric is."
Vakoch and Shostak also said that active SETI isn't as big a leap as it may seem at first glance: Our civilization has been beaming signals out into the universe unintentionally for a century, since the radio was invented.
"The reality is that any civilization that has the ability to travel between the stars can already pick up our accidental radio and TV leakage," Vakoch said. "A civilization just 200 to 300 years more advanced than we are could pick up our leakage radiation at a distance of several hundred light-years. So there are no increased dangers of an alien invasion through active SETI."
But Brin disputed this assertion, saying the so-called "barn door excuse" is a myth.
"It is very difficult for advanced civilizations to have picked us up at our noisiest in the 1980s, when we had all these military radars and these big television antennas," he said.
Shostak countered that a fear of alien invasion, if taken too far, could hamper humanity's expansion throughout the solar system, an effort that will probably require the use of high-powered transmissions between farflung outposts.
"Do you want to hamstring all that activity — not for the weekend, not just shut down the radars next week, or active SETI this year, but shut down humanity forever?" Shostak said. "That's a price I'm not willing to pay."
So the discussion and debate continues — and may continue for quite some time.
"This is the only really important scientific field without any subject matter," Brin said. "It's an area in which opinion rules, and everybody has a very fierce opinion."
February 28, 2015 / Greg Giles / Comments Off on Scientists Believe Oxygen Free Methane Based Aliens Might Exist on Icy Saturn Moon Titan
Excerpt from viralglobalnews.com A group of scientists at Cornell University believe that Titan, one of Saturn’s moons, may be a haven of life. However, it would not be in the form that human beings know. Methane based life forms might live on Titan, the scientists have said, after they created a model of an oxygen free life form which would be able to thrive in the icy, unforgiving conditions that Saturn’s moon offers. They studied the various forms of cell membranes that exist on Earth, which are made up of lipid bi-layer structures. The Cornell scientists said such membranes would not be able to exist in environments where liquid water could not be present, according to Design and Trend. Titan has plenty of lakes filled with methane, so that means it might not be habitable in the way that scientists had formerly described habitability. However, Dr. James Stevenson and his team thinks that contrarily structured membranes could offer the foundation for life to exist on Saturn’s moon. The model they created used organic nitrogen mixtures, so that the new structure could easily function on Titan in the richness of the methane that exists in liquid form there.
Dr. Stevenson said it was Isaac Asimov, the celebrated sci-fi writer, who first gave the rudimentary inspiration for the idea in the paper he penned, which was called the Not as We Know It essay. It was written about non-water-based life forms. Because Saturn’s moon is the only known celestial form in the solar system to have naturally occurring fluids on its surface, except for the Earth, the group of scientists believe it to be a possible perfect foundation for life forms to develop. Dr. Paulette Clancy, who has helped lead the group, constructed an “azotosome.” It is comparable in name origin to liposome which comes from the Greek words lipos and soma. An azotosome comes from the French word for nitrogen. Therefore, the word is describing a nitrogen body. Instead of trying to find alien life within the area that surrounds the Sun where water exists in liquid form, the group decided to try and imagine a new kind of cell, grounded on methane instead of water. Clancy and the team were dumbfounded to find that this new projected model presented an alike stability to the cell membranes already here on Earth. Dr. Clancy seemed very anxious to carry on the group’s work and find out how such compounds would truly work in the methane atmosphere. Dr. Jonathan Lunine, who is a top expert in Titan and also one of the co-authors of the study, thinks that it might be possible in the future to in fact test these theories by actually examing organic material from Saturn’s moon. In the years to come, Dr. Lunine stated that probes might be sent to Titan to gather the needed material by floating down on the methane seas of the moon of Saturn. The group discovered a compound they named acrylonitrile azotosome, which appeared to show good stability. It had a strong barricade to decomposition, and a suppleness that was similar to phospholipid membranes that exist on Earth. Acrylonitrile is a poisonous, colorless, liquid organic compound that is used in the production of acrylic fibers and thermoplastics and it is present in Titan’s atmosphere as well. They have written up about their discovery and what they believe to be possible. The scientists’ paper was printed up in the journal Science Advances on Friday.
A recently discovered black hole may help astronomers to piece together the family tree of these enigmatic cosmic objects. While most black holes are classified as either stellar-mass or the supermassive black holes that can be found at the center of some galaxies, this new find fits into neither category.
The discovery, called the intermediate-mass black hole (IMBH), has proved to be a tricky proposition. With a mass somewhere between a few hundred to a few hundred thousand times that of our own Sun, the size of these intermediates can vary widely.
This particular black hole was found in an arm of the spiral galaxy NGC-2276, and has been sensibly named NGC-2276-3c. Lying about 100 million light-years from earth, astronomers were able to tease images through the use of NASA’s Chandra X-Ray Observatory and the European Very Long Baseline Interferometry Network.
Although researchers have theorized about the existence of these IMBHs, locating one has proven elusive until now. A recent to-be-published paper by an international team of researchers delves into the specifics of NGC-2276-3c.
“Astronomers have been looking very hard for these medium-sized black holes,” study co-author Tim Roberts, of the University of Durham in the United Kingdom, said in a statement. “There have been hints that they exist, but the IMBHs have been acting like a long-lost relative that isn’t interested in being found.”
So what was found? It appears that the recently discovery has characteristics of both the smaller stellar-mass and the much larger supermassive black holes. It serves as an intermediary between the two, and some think that these intermediaries are the beginnings of what could very well become a supermassive.
The team of researchers also noted that the black holes is firing off super powerful blasts of radio jets. Think of these as material, traveling at nearly the speed of light and emitting radio waves, which are thrown out of dense objects. Our newly found black hole is shooting them out almost 2000 light-years into space. Within a radius of approximately 1000 light-years around NGC-2276-3c there are no new star formations, suggesting that the radio jets are pushing out all the gas necessary for star creation.
The full report on NGC-2276-3c should be appearing shortly in the journal Monthly Notices of the Royal Astronomical Society.