Illustration of WASP-12b in orbit about its host star (Credit: ESA/C Carreau)
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Since its discovery in 2008, WASP-12b has been an unusual planet. This 1.4 Jovian mass, gas giant lies so close to its parent star that gas is being stripped from its atmosphere. But being stripped away isn’t the only odd property of this planet’s atmosphere. A new study has shown that it’s full of carbon.
The discovery was published in today’s issue of Nature was led by Nikku Madhusudhan, a postdoctoral researcher at Princeton University in combination with the Wide Angle Search for Planets (WASP) team that originally discovered the planet. Unlike other recent studies of planetary atmospheres, this study did not employ transit spectroscopy. Instead, the team examined the reflective properties of the planet at four wavelengths, observations of which three came from another study using the Canada-France-Hawaii Telescope in Hawaii.
To determine the composition of the atmosphere, the flux of the planet at each of these wavelengths was then compared to models of planetary atmospheres with differing compositions. The models included compounds such as methane, carbon dioxide, carbon monoxide, water vapor and ammonia as well as the temperature distribution of the planet.
For a typical hot Jupiter, models have most closely fit a ratio of about 0.5 for carbon to oxygen which suggests that oxygen is more prevalent in the atmospheres, often in the form of water vapor, as well as very little methane. For WASP-12b, Madhusudhan’s team found an abundance of more than 100 times that of standard hot Jupiters for methane (CH4). When examining the carbon to oxygen ratio, they discovered a ratio greater than one implying that the planet is unusually carbon rich.
While WASP-12b is certainly not a friendly place for life, the discovery of a planet with so much carbon may hold implications for life elsewhere in the universe. Astronomers expect that the abundance was due to the formation of the planet from rocky materials high in carbon as opposed to icy bodies like comets. This suggests that there may be an entire range of carbon abundances available for planets. With the versatility of carbon for forming organic compounds, this enhanced abundance may lead to other, rocky planets covered in tar like substances rife with organics.
The team speculates that such worlds may exist in the same solar system. Previous studies have shown that WASP-12b’s orbit is not circular and some have suggested that this may indicate the presence of another body which tugs on 12b’s orbit.
A few favorite quotes and personal thoughts from NASA’s astrobiology press conference:
“So we end a week of fiction and now start with the facts,” said Dwayne Brown, Public Affairs Officer from NASA Headquarters.
From principal investigator Felisa Wolfe-Simon, a NASA astrobiology research fellow:
“I’m always interested in exceptions to the rules.”
“These are not little potatoes, these are microbes which scientists lovingly call little bugs, but they are not bugs, they are microbes that look ordinary but are doing something extraordinary.”
“We took mud from Mono Lake and wanted to see if anything would grow if it was rich in everything else it needed, but instead of phosphorous we gave it arsenic. Not only did the microbes cope but they grew and thrived and that was amazing. Nothing should have grown. We wanted to find out what was happening, and we found the microbes were taking up the arsenic, and when we isolated the DNA, we found the arsenic was in there.”
“This will help inform us of life on our own planet and provide insight when we find it somewhere else.”
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“Finding that microbes are possibly able to live without phosphorous – the idea that I’m sitting here discussing this is shocking,” said James Elser, a professor at Arizona State University. “This is quite a remarkable report.”
“I’m the curmudgeon here to throw a wet blanket on things,” said Steven Benner, a distinguished fellow from theFoundation for Applied Molecular Evolution. “I brought my Richard Feynman props with me. He said ‘science begins when you distrust the experts.’ But this is an exceptional scientific result, a clash of contradicting cultures.”
And my favorite: “This is a phenomenal finding,” said Mary Voytek, director of NASA’s Astrobiology Program. “We are talking about taking the fundamental building blocks of life and replacing one of them with an unusual, perhaps not unpredicted, but another compound. In our mind this is the equivalent, and some of us remember seeing the original Star Trek episodes, of “Devil in the Dark” and the Horta. This in our mind is the equivalent of finding that Horta which is a silicon based life, substituting carbon, which is what we think all life forms are made of, with silica. Now we are talking about an organism that we think we are talking about an organism that, if not replacing all of it, appears to be using another fundamental component of life. The story is not entirely carbon. Nitrogen, phosphorus, and the other essential elements–it is replacing arsenic for phosphorus. This is a huge deal.”
It’s life, Jim, but not as we know it.
Now that the dust and hysteria has settled from NASA’s press conference on the new astrobiology discovery, I have to admit, this was an unusual week. As always, I had the opportunity to see the Science press releases as early as last Sunday, but since I normally write about rocket launches and space mission results, I didn’t pay too much attention to this biology-related topic. It just entailed some unusual stuff here on Earth, which could mean life anywhere might be more varied and different than we thought. I knew it would be of great interest to the astrobiology community, but figured the general public would probably go “whaa?” as far as the science. But then the world started spinning out of control over NASA’s “big announcement.”
While NASA routinely sends out announcements of upcoming press conferences, and then people start to speculate of what will be announced, this one was off the charts. The fact that the press release was embargoed and “secret” – and some people had access and others didn’t — seemed to fan the flames.
There was a buzz on Twitter, on various websites, and even across the mainstream media. Personal acquaintances who normally pay no attention to my work actually started calling and emailing me to find out what I knew about NASA’s announcement about extraterrestrial life.
While some people feel that the embargoed news system is broken in today’s fast-paced, social media world, I actually like the system, and agree with the Associated Press’s Seth Borenstein, who was quoted in the Columbia Journalism Review:
“While the embargo system may have issues, I embrace it because it gives us a chance to provide context, outside comment and above all get it right,” he wrote in an e-mail. “In this hectic media environment, more than ever the world needs science reporters and editors who understand what’s happening, can tell fact from speculation, put phrases in context, be definitive and above all get it right. This whole sorry affair provides the proof of that.”
But, the CJR, asks, “Can anything be done to discourage misinformed, runway blogging that can lead to so much public confusion?”
It seems those who don’t have access to the embargoed releases want to be “first” in breaking the news. But as is often the case, the actual story is not nearly as sensational as all the speculation.
Borenstein again: “As a reporter who has covered astrobiology for more than a decade, I can tell you it has nothing to do with little green men or anything alien. Astrobiology is a series of little steps on Earth and beyond. Experienced science reporters know how to interpret the press release that got the speculation going. There is still a place for solid journalism.”
And in my bid for solid journalism, here’s my ode to the weird bacteria (with apologies to Walt Whitman):
I Sing the Bacterium Arsenic
Oh, little GFAJ-1
The potato-looking gammaproteobacteria, straight from Mono Lake
You are the arsenic to my phosphorous,
The sustenance to my poison
The arsenate backbone to your altered DNA,
The yin to the rest of the world’s yang,
The Horta to my Trekkieness,
And the reality to everyone’s wild speculation.
Mono Lake in California, with the bacteria (inset) that lives there. Credit: Science
No, NASA has not found life on another planet, but has found life here on Earth that is almost “alien” to our narrow, phosphate-based view of life. Scientists have discovered — or “trained,” actually — a type of bacteria that can live and grow almost entirely on a poison, arsenic, and incorporates it into its DNA. This “weird” form of life, which can use something other than phosphorus — what we think of as a basic building block of life — is quite different from what we think of as life on Earth. It doesn’t directly provide proof of a “shadow biosphere,” a second form of life that lives side-by-side with other life on our planet, but does suggest that the requirements for life’s beginnings and foundations may be more flexible than we thought. This means life elsewhere in the solar system and beyond could arise in a multitude of conditions.
“Our findings are a reminder that life-as-we-know-it could be much more flexible than we generally assume or can imagine,” said Felise Wolfe-Simon, lead author of a new paper in Science. “If something here on Earth can do something so unexpected, what else can life do that we haven’t seen yet?”
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The salt-loving bacteria, strain GFAJ-1 of the Halomonadaceae family of Gammaproteobacteria,came from the toxic and briny Mono Lake, near Yosemite Park in California. The lake has no outlet, so over millennia has become one of the highest natural concentrations of arsenic on Earth.
Although the bacteria did not subsist entirely on arsenic in the lake, the researchers took the bacteria in the lab grew it in Petri dishes in which phosphate salt was gradually replaced by arsenic, until the bacteria could grow without needing phosphate, an essential building block for various macromolecules present in all cells, including nucleic acids, lipids and proteins.
Using radio-tracers, the team closely followed the path of arsenic in the bacteria; from the chemical’s uptake to its incorporation into various cellular components. Arsenic had completely replaced phosphate in the molecules of the bacteria, right down its DNA.
“Life as we know it requires particular chemical elements and excludes others,” said Ariel Anbar, a biogeochemist and astrobiologist from Arizona State University. “But are those the only options? How different could life be? One of the guiding principles in the search for life on other planets, and of our astrobiology program, is that we should ‘follow the elements. Felisa’s study teaches us that we ought to think harder about which elements to follow.”
Felisa Wolfe-Simon, right, a NASA astrobiology research fellow in residence at the USGS, and Ronald Oremland, an expert in arsenic microbiology at the USGS, examine sediment in August 2009 from Mono Lake in eastern California. Credit: Henry Bortman
Wolfe-Simon added, “We took what we do know about the ‘constants’ in biology, specifically that life requires the six elements CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur) in three components, namely DNA, proteins and fats, and used that as a basis to ask experimentally testable hypotheses even here on Earth.”
The idea that arsenic might be a substitute for phosphorus in life on Earth, was proposed by Wolfe-Simon and developed into a collaboration with Anbar and theoretical physicist and cosmologist Paul Davies. Their hypothesis was published in January 2009, in a paper titled “Did nature also choose arsenic?” in the International Journal of Astrobiology.
“We not only hypothesized that biochemical systems analogous to those known today could utilize arsenate in the equivalent biological role as phosphate,” said Wolfe-Simon “but also that such organisms could have evolved on the ancient Earth and might persist in unusual environments today.”
This new research is the first time that shows a microorganism is able to use a toxic chemical to sustain growth and life.
No, NASA is probably not announcing extraterrestrial life. And though this stock image shows a water bear, these cool little creatures come from right here on Earth (and have nothing to do with the announcement, but are scary looking when magnified). Image Credit: NASA
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You may have heard in your wanderings through the blogosphere and in the internet today that NASA will be holding a press conference on December 2nd in which they will make an announcement regarding information the search for extraterrestrial life. And that this announcement involves astrobiology, the study of life outside what we know about here on Earth. While true, it is nothing to get worked up about.
Speculation abounds that this is, “the big one,” and that an announcement will be made that extraterrestrial life has been discovered. You can find this speculation at Kottke.org, io9, Gawker, and a lot of other places.
To be clear, there is almost no chance that the press release will be announcing little green men or little brown bacteria anywhere. Follow along for the long explanation below the fold.
Here’s what the press release is titled: “NASA Sets News Conference on Astrobiology Discovery: Science Journal Has Embargoed Details Until 2 p.m. EST On Dec. 2”. All this means is that Science Journal will be publishing some results related to astrobiology that are under embargo until that time. The embargo system is a basically a way of allowing journalists to see scientific results and get interviews and do research on an article before it’s published, but only if they promise to publish their information after the original publication does so. It makes sense, and it works most of the time to the benefit of almost everyone.
NASA regularly – like every day – announces upcoming press conferences and releases, and embargoed press releases float around to science writers like those of us here at Universe Today. This in itself is nothing out of the ordinary, and anyone with an email address can sign up to have these announcements delivered to their inbox or view them on NASA’s website. These emails are meant mainly to notify members of the press that there is something coming up worthy of being a phone-in listener of, the details of which require you to have press credentials.
The press release goes on to say,
“NASA will hold a news conference at 2 p.m. EST on Thursday, Dec. 2, to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life. Astrobiology is the study of the origin, evolution, distribution and future of life in the universe.
The news conference will be held at the NASA Headquarters auditorium at 300 E St. SW, in Washington. It will be broadcast live on NASA Television and streamed on the agency’s website at http://www.nasa.gov.
Participants are:
– Mary Voytek, director, Astrobiology Program, NASA Headquarters, Washington
– Felisa Wolfe-Simon, NASA astrobiology research fellow, U.S. Geological Survey, Menlo Park, Calif.
– Pamela Conrad, astrobiologist, NASA’s Goddard Space Flight Center, Greenbelt, Md.
– Steven Benner, distinguished fellow, Foundation for Applied Molecular Evolution, Gainesville, Fla.
– James Elser, professor, Arizona State University, Tempe”
And that’s about it. My first reaction to this was that they had potentially made the discovery of exotic, new organic molecules in an exoplanetary atmosphere, or that some chemical conducive to the existence of life as we know it was possibly found on some body in the Solar System. Announcements like this come out of NASA all of the time.
Just because some of the participants do work in fields that are related to oceanography or ecology or biology, does not mean that their services are required here to help make an announcement that life other than that on Earth has been discovered, as other speculative bloggers might think.
As Nancy wrote in a post earlier today, extraterrestrial life is very much of interest to Universe Today readers. Which is why she’ll be listening in on that news conference Thursday, and reporting what findings are released.
Extraterrestrial life is very much of interest to probably most of the population of our planet, too, and the fact that we have the tools necessary to potentially make this discovery within the next few hundred years (or sooner), is really, really exciting.
But just because it’s exciting doesn’t mean we have to jump all over a NASA press release that includes the words “extraterrestrial life” or “precursor to life on Mars” and make wild speculations. When that announcement is made (or if, depending on how you choose to solve the Drake Equation), you can be sure that it will be very closely guarded until being made public, and after that the President will likely have some things to say.
For some more level-headed analysis, Keith Cowing at Nasa Watch has some much more reasonable speculation that the announcement involves arsenic biochemistry. The Bad Astronomer, Phil Plait, also has a good debunking of the rampant speculation, and makes some good points about how NASA can create press releases in the future that have better-worded announcements.
So calm down – but don’t stop looking up! Keep being excited about all of the genuinely cool and exciting developments we’re currently making with regards to space.
An infrared photo of the Small Magellanic Cloud taken by Spitzer is shown here in this artist's illustration, with two callouts. The middle callout shows a magnified view of an example of a planetary nebula, and the right callout shows an even further magnified depiction of buckyballs, which consist of 60 carbon atoms arranged like soccer balls. Image credit: NASA/JPL-Caltech
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Earlier this year, astronomers using the Spitzer Space Telescope announced they had found – for the first time — carbon molecules, known as “buckyballs,” in space. They were detected in one planetary nebula, and even though they were predicted to be rather prevalent out in space, no one was really sure. Until now. They’ve now been found in the space between stars, and around four more planetary nebulae, with one dying star in a nearby galaxy holding a staggering quantity of buckyballs — the equivalent mass of 15 times that of Earth’s Moon.
“It turns out that buckyballs are much more common and abundant in the universe than initially thought,” said astronomer Letizia Stanghellini of the National Optical Astronomy Observatory in Tucson, Ariz. “Spitzer had recently found them in one specific location, but now we see them in other environments. This has implications for the chemistry of life. It’s possible that buckyballs from outer space provided seeds for life on Earth.”
Buckyballs are soccer-ball-shaped molecules that were first observed in a laboratory 25 years ago, and are named for their resemblance to architect Buckminster Fuller’s geodesic domes, which have interlocking circles on the surface of a partial sphere. Also known as C60, and Fullerenes, they are the third major form of pure carbon; graphite and diamond are the other two. They have been thought to be common in space since they have been found in meteorites, and also in more everyday materials such as soot.
While two different studies announced today confirm that buckyballs could be widespread in space, they are turning up in places where astronomers thought they couldn’t exist. So, obviously we don’t have these molecules fully figured out yet.
All the planetary nebulae in which buckyballs have been detected are rich in hydrogen. This goes against what researchers thought for decades — they had assumed that, as is the case with making buckyballs in the lab, hydrogen could not be present. The hydrogen, they theorized, would contaminate the carbon, causing it to form chains and other structures rather than the spheres, which contain no hydrogen at all.
“We now know that fullerenes and hydrogen coexist in planetary nebulae, which is really important for telling us how they form in space,” said Anibal García-Hernández from the Instituto de Astrofísica de Canarias, Spain, lead author, working with Stanghellini on a paper appearing online Oct. 28 in the Astrophysical Journal Letters.
Using Spitzer, this team found the buckyballs around three dying sun-like stars, called planetary nebulae, in the our own Milky Way galaxy, plus in another planetary nebula the Small Magellanic Cloud, a nearby galaxy. This was particularly exciting to the researchers, because, in contrast to the planetary nebulae in the Milky Way, the distance to this galaxy is known. Knowing the distance to the source of the buckyballs meant that the astronomers could calculate their quantity — two percent of Earth’s mass, or the equivalent mass of 15 times that of Earth’s Moon.
Planetary nebulae are made of material shed from the dying stars.
Another Spitzer study about the discovery of buckyballs in space was also recently published in the Astrophysical Journal Letters, (October 10, 2010) and was led by Kris Sellgren of Ohio State University, Columbus. This study found that buckyballs are also present in the space between stars, but not too far away from young solar systems.
They were found among two nebulae; NGC 2023, located near the well-known Horsehead Nebula in the constellation of Orion, and the second, NGC 7023, known as the Iris Nebula, in the constellation Cepheus.
These are the largest molecules ever discovered floating between the stars. Astronomers aren’t sure yet if these cosmic balls formed in a nearby planetary nebula and wandered away, or if they perhaps can spring up in interstellar space.
“It’s exciting to find buckyballs in between stars that are still forming their solar systems, just a comet’s throw away,” Sellgren said. “This could be the link between fullerenes in space and fullerenes in meteorites.”
Since carbon is the key building block for life as we know it, their perhaps prevalent existence in space is intriguing.
“Now that there are buckyballs confirmed in the interstellar medium and in circumstellar space, it’s likely that chemists will get more interested in the astrobiological implications of these fascinating molecules,” Sellgren said.
Sometimes topics segue perfectly. With the recent buzz about habitable planets, followed by the raining on the parade articles we’ve had about the not insignificant errors in the detections of planets around Gliese 581 as well as finding molecules in exoplanet atmospheres, it’s not been the best of times for finding life. But in a comment on my last article, Lawrence Crowell noted: “You can’t really know for sure whether a planet has life until you actually go there and look on the ground. This is not at all easy, and probably it is at best possible to send a probe within a 25 to 50 light year radius.”
This is right on the mark and happens to be another topic that’s been under some discussion on arXiv recently in a short series of paper and responses. The first paper, accepted to the journal Astrobiology and led by Jean Schneider of the Observatory of Paris-Meudon, seeks to describe “the far future of exoplanet direct characterization”. In general, this paper discusses where the study of exoplanets could go from our current knowledge base. It proposes two main directions: Finding more planets to better survey the parameter space planets inhabit, or more in depth, long-term studying of the planets we do know.
But perhaps the more interesting aspect of the paper, and the one that’s generated a rare response, is what can be done should we detect a planet with promising characteristics relatively nearby. They first propose trying to directly image the planet’s surface and calculate the diameter of a telescope capable of doing so would be roughly half as large as the sun. Instead, if we truly wish to get a direct image, the best bet would be to go there. They quickly address a few of the potential challenges.
The first is that of cosmic rays. These high energy particles can wreak havoc on electronics. The second is simple dust grains. The team calculates that an impact with “a 100 micron interstellar grain at 0.3 the speed of light has the same kinetic energy than a 100 ton body at 100 km/hour”. With present technology, any spacecraft equipped with sufficient shielding would be prohibitively massive and difficult to accelerate to the velocities necessary to make the trip worthwhile.
But Ian Crawford, of the University of London, thinks that the risk posed by such grains may be overstated. Firstly, Crawford believes Schneider’s requirement of 30% of the speed of light is somewhat overzealous. Instead, most proposals of interstellar travel by probes generally use a value of 10% of the speed of light. In particular, the most exhaustive proposal yet created, (the Daedalus project) only attempted to achieve a velocity of 0.12c. However, the ability to produce such a craft was well beyond the means at the time. But with the advent of miniaturization of many electronic components, the prospect may need to be reevaluated.
Aside from the overestimate on necessary velocities, Crawford suggests that Schneider’s team overstated the size of dust grains. In the solar neighborhood, dust grains are estimated to be nearly 100 times smaller than reported by Schneider’s team. The combination of the change in size estimation and that of velocity takes the energy released on collision from a whopping 4 x 107 Joules, to a mere 4.5 Joules. At absolute largest, recent studies have shown that the upper limit for dust particles is more in the range of 4.5 micrometers.
Lastly, Crawford suggests that there may be alternative ways to offer shielding than the brute force wall of mass. If a spacecraft were able to detect incoming particles using radar or another technique, it is possible that it could destroy the incoming particles using lasers, or deflect it using a electromagnetic field.
But Schneider wasn’t finished. He issued a response to Crawford’s response. In it, he criticizes Crawford’s optimistic vision of using nuclear or anti-matter propulsion systems. He notes that, thus far, nuclear propulsion has only been able to produce short impulses instead of continuous thrust and that, although some electronics have been miniaturized, the best analogue yet developed, the National Ignition Facility, is, “with all its control and cooling systems, is presently quite a non-miniaturized building.”
Anti-matter propulsion may be even more difficult. Currently, our ability to produce anti-matter is severely limited. Schneider estimates that it would take 200 terrawatts of energy to produce the required amounts. Meanwhile, the overall energy of the entire Earth is only 20 terrawatts.
In response to the charge of overestimation, Schneider notes that, although such large dust grains would be rare, but “even two lethal or severe collisions are prohibitory”, but does not go on to make any honest estimations of what the actual probability of such a collision would be.
Ultimately, Schneider concludes that all discussion is, at best, extremely preliminary. Before any such undertaking would be seriously considered, it would require “a precursor mission to secure the technological concept, including shielding mechanisms, at say 500 to 1000 Astronomical Units.” Ultimately, Schneider and his team seems to remind us that the technology is not yet there and that there are legitimate threats we must address. Crawford, on the other hand suggests that some of these challenges are ones that we may already be well on the road to addressing and constraining.
Possible Phyllosilicate-Rich Area in Syrtis Major. Credit: NASA/JPL/University of Arizona
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Data from the Mars Reconnaissance Orbiter suggests that there could be habitable environments underground on Mars – in the past, and perhaps even today. Scientists discovered evidence of long-sought-after hydrothermally altered carbonate-bearing rocks which were once deep within the Red Planet, exposed within an impact crater. “Carbonate rocks have long been a Holy Grail of Mars exploration for several reasons,” said Joseph Michalski from the Planetary Science Institute. He explained that on Earth, carbonates form with the ocean and within lakes, so the same could be true for ancient Mars. “Such deposits could indicate past seas that were once present on Mars. Another reason is because we suspect that the ancient Martian atmosphere was probably denser and CO2-rich, but today the atmosphere is quite thin so we infer that the CO2 must have gone into carbonate rocks somewhere on Mars.”
This unique mineralogy was spotted within the central peak of a crater to the southwest of a giant Martian volcanic province named Syrtis Major. With infrared spectra from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), planetary geologists detected the hydrothermal minerals from their spectroscopic fingerprints. Visible images from the HiRISE camera (High Resolution Imaging Science Experiment) on board MRO show that the carbonates and hydrated silicate minerals occur within deformed bedrock that was exhumed by an ancient meteor impact that poked through the volcanic upper crust of Mars.
The carbonate-bearing rocks were once likely about 6 km (about 4 miles) underground. The carbonate minerals exist along with hydrated silicate minerals of a likely hydrothermal origin.
Syrtis Major Planum Channel and Depression. Credit: NASA/JPL/University of Arizona
While this is not the first detection of carbonates on Mars, Michalski said, “This detection is significant because it shows other carbonates detected by previous workers, which were found in a fairly limited spatial extent, were not a localized phenomenon. Carbonates may have formed over a very large region of ancient Mars, but been covered up by volcanic flows later in the history of the planet. A very exciting history of water on Mars may be simply covered up by younger lava!”
The discovery also has implications for the habitability of the Martian crust. “The presence of carbonates along with hydrothermal silicate minerals indicates that a hydrothermal system existed in the presence of CO2 deep in the Martian crust,” Michalski says. “Such an environment is chemically similar to the type of hydrothermal systems that exist within the ocean floor of Earth, which are capable of sustaining vast communities of organisms that have never seen the light of day.
“The cold, dry surface of Mars is a tough place to survive, even for microbes. If we can identify places where habitable environments once existed at depth, protected from the harsh surface environment, it is a big step forward for astrobiological exploration of the red planet.”
Michalski and co-author Paul B. Niles of NASA Johnson Space Center recently published the results in a paper titled “Deep crustal carbonate rocks exposed by meteor impact on Mars” in Nature Geoscience.
Titan's thick haze. Image: NASA/JPL/Space Science Institute.
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Saturn’s moon Titan has long been thought to be an analog of early Earth, and a recent experiment demonstrates that amino acids and nucleotide bases — which are the basic building blocks of life on Earth – could very easily be under production in Titan’s hazy atmosphere. “Our intention was to figure out what goes on in Titan’s atmosphere using high resolution mass spectrometry,” said Sarah Horst, from the University of Arizona, a member of an international team conducting the research. “We found there could be a high number of some incredibly complex molecules being created.”
Two recent exciting discoveries led the team to try and find out more about Titan’s atmosphere: first, the discovery of high energy oxygen ions flowing into Titan’s atmosphere, and second, that there are high heavy molecular ions in the atmosphere – neither of which were expected.
“When you put two discoveries together, that leads us to possibility that oxygen can get incorporated into these large molecules and in turn, that may be incorporated into life,” Horst said in press briefing at the American Astronomical Society’s Division of Planetary Sciences meeting this week.
The intense radiation that hits the top of Titan’s thick atmosphere is capable of breaking apart even very stable molecules. The international team wanted to understand what happens as these molecules are broken apart in the atmosphere.
Working with a team in France, Horst, a graduate student, and her professor Roger Yelle, filled a reaction chamber with Titan-like atmosphere, (a cold plasma consisting of nitrogen, methane and carbon monoxide), and infused radio-frequency radiation as an energy source.
“What happens is that aerosols form in levitation — they float while forming — so this probably is very representative of Titan’s atmosphere,” Horst said. “We end up with really cool looking aerosols that have very similar sizes to aerosols that are inferred in Titan’s atmosphere.”
The molecules discovered in the aerosols include the five nucleotide bases used by life on Earth (cytosine, adenine, thymine, guanine and uracil) and the two smallest amino acids, glycine and alanine.
“The experiment showed that Titan’s atmosphere is capable of producing extremely complex molecules and has the potential for producing molecules that are important for life on Earth,” Horst said, but tempered her statement by adding, “however, this doesn’t mean there is life on Titan.”
She said if there were life on Titan, mostly likely it would use molecules that life on Earth would not use, as due to lack of liquid water, life would be completely different.
“But this tells that it is possible to make very complex molecules in the outer parts of an atmosphere,” Horst said. “We don’t need liquid water, we don’t need a surface.”
This also provides another option to how life may have started on Earth. The two main theories for how life began on Earth is that it was brought here by comets or asteroids or that it formed from a primordial soup zapped to life from lightning. But it may have formed from a primordial haze high in Earth’s atmosphere.
“This helps us to understand what processes began life on Earth and what could be happening on other exoplanets in the galaxy,” Horst said.
Image from the 1951 move "The Day the Earth Stood Still." Credit: IMBD.com
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UPDATE: OK, this seemed like a cool story, reported by many news sources, but apparently, it isn’t true. The Discovery Discoblog has the details. . I guess there was a truth abduction.
If aliens ever visit Earth and actually do use the time-worn phrase, “Take me to your leader,” or if a SETI search ever finds a signal of an alien civilization saying “hello,” there may be someone ready and waiting to respond. The United Nations is considering selecting a special ambassador to be the first point of contact for aliens wishing to communicate with Earth. Mazlan Othman, a Malaysian astrophysicist and currently head of the UN’s Office for Outer Space Affairs (UNOOSA) is expected to be named to the position.
“Othman is absolutely the nearest thing we have to a ‘take me to your leader’ person,” said Richard Crowther, in an article in the UK newspaper, the Telegraph.
Crowther is an expert in space law at the UK space agency who leads delegations to the UN. Reportedly, the plan to make UNOOSA the coordinating body for dealing with alien encounters will be debated by UN scientific advisory committees and should eventually reach the body’s general assembly.
The proposal is said to have been prompted by the recent discovery of hundreds extrasolar planets, which makes the discovery of extraterrestrial life more probable than ever.
Ms. Othman said in a recent talk to fellow scientists, “The continued search for extraterrestrial communication, by several entities, sustains the hope that someday human kind will received signals from extraterrestrials. When we do, we should have in place a coordinated response that takes into account all the sensitivities related to the subject. The UN is a ready-made mechanism for such coordination.”
But will visiting ET’s be greeted with open arms, or with a conditional sterilization? Under the Outer Space Treaty written in 1967, (which UNOOSA oversees) UN members agreed to protect Earth against contamination by alien species by “sterilizing” them. Reportedly, Othman supports a more tolerant approach.
But physicist Stephen Hawking has warned that aliens should be treated with caution.
“I imagine they might exist in massive ships,” he said, “having used up all the resources from their home planet. The outcome for us would be much as when Christopher Columbus first landed in America, which didn’t turn out very well for the Native Americans.” Alien abduction would be the least of our worries.
In the meantime, US citizens wishing to be ‘ambassadors’ for space exploration should consider joining JPL’s Solar System Ambassador program. This is a great program (which I am honored to participate in) to spread the word about the wonders of excitement of space exploration and science. Find out more at the SSA website, and if interested, the program is now taking applications for new ambassadors. Hurry, as applications are being taken until September 30, 2010.
This plot of data from NASA's Spitzer Space Telescope tells astronomers that a dusty planetary smashup probably occurred around a pair of tight twin, or binary, stars. Image credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA
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Astronomers studying double star systems where the two stars are extremely close have found a pattern of destruction. While there probably isn’t a Star Wars-like Death Star roaming the Universe, tight binary systems might provide the equivalent of Darth Vader’s favorite weapon. “This is real-life science fiction,” said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics. “Our data tell us that planets in these systems might not be so lucky — collisions could be common. It’s theoretically possible that habitable planets could exist around these types of stars, so if there happened to be any life there, it could be doomed.”
Using the Spitzer Space Telescope, Drake and his team spotted a surprisingly large amount of dust around three mature, close-orbiting star pairs, that might be the aftermath of tremendous planetary collisions.
Drake is the principal investigator of the research, published in the Aug.19 issue of the Astrophysical Journal Letters.
The particular class of binary stars in the study are extremely close together. Named RS Canum Venaticorums, or RS CVns for short, they are separated by only about 3.2-million kilometers (two-million miles ), or two percent of the distance between Earth and our sun. The binaries orbit around each other every few days, with one face on each star perpetually locked and pointed toward the other.
These stars are familiarly like our own Sun – about the same size and probably about a billion to a few billion years old — roughly the age of our sun when life first evolved on Earth. But these stars spin much faster, and, as a result, have powerful magnetic fields, and giant, dark spots. The magnetic activity drives strong stellar winds — gale-force versions of the solar wind — that slow the stars down, pulling the twirling duos closer over time.
This is not a good scenario for planetary survival.
As the stars cozy up to each other, their gravitational influences change, and this could cause disturbances to planetary bodies orbiting around both stars. Comets and any planets that may exist in the systems would start jostling about and banging into each other, sometimes in powerful collisions. This includes planets that could theoretically be circling in the double stars’ habitable zone, a region where temperatures would allow liquid water to exist. Though no habitable planets have been discovered around any stars beyond our sun at this point in time, tight double-star systems are known to host planets; for example, one system not in the study, called HW Vir, has two gas-giant planets.
“These kinds of systems paint a picture of the late stages in the lives of planetary systems,” said Marc Kuchner, a co-author from NASA Goddard Space Flight Center. “And it’s a future that’s messy and violent.”
The temperatures around these systems measured by Spitzer are about the same as molten lava. The astronomers says that dust normally would have dissipated and blown away from the stars by this mature stage in their lives. They conclude that something — most likely planetary collisions — must therefore be kicking up the fresh dust. In addition, because dusty disks have now been found around four, older binary systems, the scientists know that the observations are not a fluke. Something chaotic is very likely going on.
If any life forms did exist in these star systems, and they could look up at the sky, they would have quite a view. Marco Matranga, lead author of the paper, also from Harvard-Smithsonian said, “The skies there would have two huge suns, like the ones above the planet Tatooine in ‘Star Wars.'”
The research was published in the Aug.19 issue of the Astrophysical Journal Letters.
