Posted on by Tammy Plotner

Planetary Habitability Index Proposes A Less “Earth-Centric” View In Search Of Life

Artist concept of an exoplanet. Credit: David A. Hardy.

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It’s a given. It won’t be long until human technology will expand our repertoire of cataloged exoplanets to astronomical levels. Of these, a huge number will be considered within the “habitable zone”. However, isn’t it a bit egotistical of mankind to assume that life should be “as we know it”? Now astrobiologists/scientists like Dirk Schulze-Makuch with the Washington State University School of Earth and Environmental Sciences and Abel Mendez from the University of Puerto Rico at Aricebo are suggesting we take a less limited point of view.

“In the next few years, the number of catalogued exoplanets will be counted in the thousands. This will vastly expand the number of potentially habitable worlds and lead to a systematic assessment of their astrobiological potential. Here, we suggest a two-tiered classification scheme of exoplanet habitability.” says Schulze-Makuch (et al). “The first tier consists of an Earth Similarity Index (ESI), which allows worlds to be screened with regard to their similarity to Earth, the only known inhabited planet at this time.”

Right now, an international science team representing NASA, SETI,the German Aerospace Center, and four universities are ready to propose two major questions dealing with our quest for life – both as we assume and and alternate. According to the WSU news release:

“The first question is whether Earth-like conditions can be found on other worlds, since we know empirically that those conditions could harbor life,” Schulze-Makuch said. “The second question is whether conditions exist on exoplanets that suggest the possibility of other forms of life, whether known to us or not.”

Within the next couple of weeks, Schulze-Makuch and his nine co-authors will publish a paper in the Astrobiology journal outlining their future plans for exoplanet classification. The double approach will consist of an Earth Similarity Index (ESI), which will place these newly found worlds within our known parameters – and a Planetary Habitability Index (PHI), that will account for more extreme conditions which could support surrogate subsistence.

“The ESI is based on data available or potentially available for most exoplanets such as mass, radius, and temperature.” explains the team. “For the second tier of the classification scheme we propose a Planetary Habitability Index (PHI) based on the presence of a stable substrate, available energy, appropriate chemistry, and the potential for holding a liquid solvent. The PHI has been designed to minimize the biased search for life as we know it and to take into account life that might exist under more exotic conditions.”

Assuming that life could only exist on Earth-like planets is simply narrow-minded thinking, and the team’s proposal and modeling efforts will allow them to judiciously filter new discoveries with speed and high level of probability. It will allow science to take a broader look at what’s out there – without being confined to assumptions.

“Habitability in a wider sense is not necessarily restricted to water as a solvent or to a planet circling a star,” the paper’s authors write. “For example, the hydrocarbon lakes on Titan could host a different form of life. Analog studies in hydrocarbon environments on Earth, in fact, clearly indicate that these environments are habitable in principle. Orphan planets wandering free of any central star could likewise conceivably feature conditions suitable for some form of life.”

Of course, the team admits an alien diversity is surely a questionable endeavor – but why risk the chance of discovery simply on the basis that it might not happen? Why put a choke-hold on creative thinking?

“Our proposed PHI is informed by chemical and physical parameters that are conducive to life in general,” they write. “It relies on factors that, in principle, could be detected at the distance of exoplanets from Earth, given currently planned future (space) instrumentation.”

Original News Source: WSU News. For Further Reading: A Two-Tiered Approach to Assessing the Habitability of Exoplanets.

Posted on by Jason Major

Europa’s Hidden Great Lakes May Harbor Life

Chaos terrain on Europa points to subsurface lakes, new research suggests. (NASA/JPL/Ted Stryk)

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New research on Jupiter’s ice-covered moon Europa indicates the presence of a subsurface lake buried beneath frozen mounds of huge jumbled chunks of ice. While it has long been believed that Europa’s ice lies atop a deep underground ocean, these new findings support the possibility of large pockets of liquid water being much closer to the moon’s surface — as well as energy from the Sun — and ultimately boosting the possibility it could contain life.

During a press conference today, November 16 at 1 p.m. EST, researchers Britney Schmidt, Tori Hoeler, Louise Prockter and Tom Wagner presented new theories concerning the creation of “chaos terrain” on Europa.

Chaos terrain is exactly what it sounds like: irregularly-shaped landforms and surface textures on a world. In the case of Europa, the terrain is made of water ice that evidence shows has been loosened by the motion of liquid water beneath, expanded, and then has refrozen into hills and jagged mounds.

Topographic data shows the chaos terrain elevations above the surrounding surface. Reds and purples are the highest elevations. Credit: NASA

These mounds are visible in topographic data acquired by the Galileo spacecraft in 1998.

During the presentation a good analogy for the processes at work on Europa was made by Britney Schmidt, a postdoctoral fellow at the Institute for Geophysics, University of Texas at Austin and lead author of the paper. She demonstrated the formation of Europa’s “mosh pit of icebergs” using a drinking glass partially filled with ice cubes. When water was added to the glass, the ice cubes naturally rose up and shifted orientation. Should the water beneath them refreeze, as it would in the frigid environments found in the Jovian system, the ice cubes would be held fast in their new expanded, “chaotic” positions.

“Now we see evidence that it’s a thick ice shell that can mix vigorously, and new evidence for giant shallow lakes. That could make Europa and its ocean more habitable.”

– Britney Schmidt, lead author

Similar processes have also been seen occurring on Earth, both in Antarctica along the edges of ice shelves and in Greenland, where glaciers continually break apart and flow into the sea – often rolling over themselves and each other in the process.

Europa's "Great Lake." Scientists speculate many more exist throughout the shallow regions of the moon's icy shell. Image Credit: Britney Schmidt/Dead Pixel FX/Univ. of Texas at Austin.

The importance of these findings is that scientists finally have a model that demonstrates how Europa’s deep liquid ocean interacts with the ice near its surface in such a way as to allow for the transportation of energy and nutrients.

“This is the first time that anyone has come up with an end-to-end model that explains what we see on the surface,” said APL senior planetary scientist Louise Prockter.

With such strong evidence for this process, the likelihood that Europa could harbor environments friendly to life goes up dramatically.

“The potential for exchange of material between the surface and subsurface is a big key for astrobiology,” said Wes Patterson, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., and a co-author of the study. “Europa’s subsurface harbors much of what we believe is necessary for life but chemical nutrients found at the surface are likely vital for driving biology.”

Although the research favors the existence of these lakes, however, confirmation of such has not yet been found. That will require a future mission to Europa and the direct investigation of its icy surface – and what lies beneath.

Luckily a Europa mission was recently rated as one of the highest priority flagship missions by the National Research Council’s Planetary Science Decadal Survey and is currently being studied by NASA.

“If we’re ever to send a landed mission to Europa, these areas would be great places to study,” Prockter said.

Read more about this discovery in the Johns Hopkins University Applied Physics Laboratory press release, or in the NASA news release here. Also, watch the full conference recorded on Ustream below:

Posted on by Paul Scott Anderson

Is There a Methane Habitable Zone?

A sunlight glint off a methane lake near Titan’s north pole (infrared image). Credit: NASA/JPL/University of Arizona/DLR

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For a long time now, we have heard the mantra “follow the water” when it comes to searching for life elsewhere. Life as we know it here on Earth requires liquid water, whether it is tiny microbes or elephants. It has thus been assumed that carbon-based life somewhere else that is basically similar to ours in its chemical makeup (another assumption) would also require water for its survival and growth. But is that necessarily true? In recent years, more consideration has been given to the possibility that life could develop in other mediums as well, besides water. A liquid is still ideal, for allowing the necessary molecules to bond together. So what are the alternatives? Well, one of the most interesting possibilities is something we have already seen now elsewhere in our solar system – liquid methane.

It should be noted that the importance of water cannot be overlooked. According to Chris McKay, an astrobiologist and planetary scientist at NASA’s Ames Research Center, “We live on a planet where water is a liquid and we have adapted and evolved to work with that liquid. Life has very cleverly used the properties of water to do things not just in terms of solution, but in using the strong polarity of that solution to its advantage in terms of hydrophobic and hydrophilic bonds, and using the very structure of water to help align molecules.”

But McKay also published a paper In the journal Planetary and Space Science last April, postulating how life on some worlds could use liquid methane in place of water. There could be planets orbiting red dwarf stars, which are smaller and cooler than our Sun, and could have a “liquid methane habitable zone” where methane could exist as a liquid on the surface of planets orbiting within that zone. They could also exist around Sun-like stars, although they would be easier to detect around the smaller, dimmer red dwarf stars. But there is already one methane world that we know of, much closer to home…

Orbiting the sixth planet out from the Sun, Saturn, is a moon which in some ways is eerily Earth-like, with rain, rivers, lakes and seas – Titan. It is the first world we’ve found so far that has liquid on its surface like Earth does. But there is one major difference; the liquid is not water, it is liquid methane/ethane. With temperatures far colder than anywhere on Earth at –179 degrees Celsius, water cannot exist as a liquid, it is frozen as hard as rock. But methane can exist as a liquid under those conditions and indeed does on Titan. Beneath an atmosphere that is thicker than ours (but also made primarily of nitrogen), the surface of Titan has been modified in much the same way as Earth’s; liquid methane plays the same role there as water does here, with a complete hydrological cycle. It is like a familiar-looking but colder version of our planet, which has raised the question of whether an environment like this could even support life of some kind.

McKay had also previously suggested that methane-based life could consume hydrogen, acetylene and ethane, and exhale methane instead of carbon-dioxide. This would result in a depletion of hydrogen, acetylene and ethane on the surface of Titan. Interestingly, this is just what has been found by the Cassini spacecraft, although McKay is quick to caution that there could still be other more likely explanations. There is still a lot we don’t know about Titan. Whatever the explanation, there is some interesting chemistry going on.

At the very least, Titan is thought to represent conditions similar to those on the early Earth, a sort of primordial Earth in deep-freeze. That alone could provide vital clues as to how to life took hold on our planet. If there are other planets or moons out there that are similar, as now seems likely, they could also reveal valuable insights into the question of the origin of life, whether there is anything swimming in those cold lakes and seas or not. While water is still considered the primary liquid medium of choice, liquid methane could be the next best thing, and if we have learned anything, it is how amazingly adaptive and resourceful life can be, perhaps even more than we think.

Posted on by Paul Scott Anderson

‘Sweet Spots’ for Formation of Complex Organic Molecules Discovered in Our Galaxy

Credit: NASA

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Astrobiologists have discovered regions in our galaxy which might have the greatest potential for producing very complex organic molecules, the starting point for the development of life. We’ve heard before about “follow the water” in the search for life; in this case it may be “follow the methanol”…

The scientists involved, from Rensselaer Polytechnic Institute in Troy, New York, began a search for methanol, a key ingredient in the synthesis of organic molecules. According to Douglas Whittet, lead researcher of the study, “Methanol formation is the major chemical pathway to complex organic molecules in interstellar space.” The idea is to look for areas where there is rich methanol production occurring. In the large clouds of dust and gas that give birth to new stars, there are simpler organic molecules like carbon monoxide. Under the right conditions, carbon monoxide on the surfaces of dust grains can interact with hydrogen, also found in the clouds, to create methanol. Methanol can then become a steppingstone to create the more complex organic molecules, the types needed for life itself. But how much methanol is out there, and where?

It appears to be most abundant around a small number of newly-formed stars, where it makes up to 30 percent of the material around those stars. In other areas though, it is in much smaller amounts, or none at all. In the cold dust and gas clouds that will eventually produce new stars, it was found to exist in the 1 to 2 percent range. Hence, there appear to be “sweet spots” where conditions are suitable for the chain reactions to occur, depending on how fast the needed molecules can reach the dust grains. It can mean the difference between a “dead end” for additional development or an “organic bloom.” As described by Whittet: “If the carbon monoxide molecules build up too quickly on the surfaces of the dust grains, they don’t get the opportunity to react and form more complex molecules. Instead, the molecules get buried in the ices and add up to a lot of dead weight. If the buildup is too slow, the opportunities for reaction are also much lower.”

So some places may be much more likely to have the conditions necessary for the development of life than others. What about our own solar system? How does it compare? By studying the methanol amounts in comets, relics from the beginning of the solar system, the scientists have concluded that the methanol abundance back then was about average. Not a dearth of the stuff, but not a “sweet spot” really, either. Yet here we are… or, as Whittet put it, “This means that our solar system wasn’t particularly lucky and didn’t have the large amounts of methanol that we see around some other stars in the galaxy. But, it was obviously enough for us to be here.”

The paper, titled “Observational constraints on methanol production in interstellar and preplanetary ices,” will be published in the Nov. 20 edition of The Astrophysical Journal and is a collaboration between Rensselaer, NASA Ames Research Center, the SETI Institute and Ohio State University.

Posted on by Nancy Atkinson

No Alien Visits or UFO Coverups, White House Says

Movie poster from 'Independence Day.' Credit: 20th Century Fox

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The White House has responded to two petitions asking the US government to formally acknowledge that aliens have visited Earth and to disclose to any intentional withholding of government interactions with extraterrestrial beings. “The U.S. government has no evidence that any life exists outside our planet, or that an extraterrestrial presence has contacted or engaged any member of the human race,” said Phil Larson from the White House Office of Science & Technology Policy, on the WhiteHouse.gov website. “In addition, there is no credible information to suggest that any evidence is being hidden from the public’s eye.”

5,387 people had signed the petition for immediately disclosing the government’s knowledge of and communications with extraterrestrial beings, and 12,078 signed the request for a formal acknowledgement from the White House that extraterrestrials have been engaging the human race.

“Hundreds of military and government agency witnesses have come forward with testimony confirming this extraterrestrial presence,” the second petition states. “Opinion polls now indicate more than 50% of the American people believe there is an extraterrestrial presence and more than 80% believe the government is not telling the truth about this phenomenon. The people have a right to know. The people can handle the truth.”

These petitions come from an Obama Administration initiative called ‘We the People’ which has White House staffers respond and consider taking action on any issue that receives at least 25,000 online signatures. Regarding these two petitions, the White House promised to respond if the petitions got 17,000 or more signatures by Oct. 22.

Larson stressed that the facts show that there is no credible evidence of extraterrestrial presence here on Earth. He pointed out that even though many scientists have come to the conclusion that the odds of life somewhere else in the Universe are fairly high, the chance that any of them are making contact with humans are extremely small, given the distances involved.

But that doesn’t mean we aren’t searching, there is just no evidence yet. Larson mentioned SETI (correctly noting that this at first was a NASA effort, but is now funded privately) keeping an “ear” out for signals from any intelligent extraterrestrials, with none found so far. He also added that the Kepler spacecraft is searching for Earth-like planets in the habitable zones around other stars, and that the Curiosity rover will launch to Mars this month to “assess what the Martian environment was like in the past to see if it could have harbored life.”

Regarding any evidence for alien life, all anyone has now is “statistics and speculation,” said Larson. “The fact is we have no credible evidence of extraterrestrial presence here on Earth.”

Whether or not this will appease or satisfy any conspiracy theorists or UFO believers is yet to be seen, but it is gratifying to see the White House respond in such a no-nonsense manner.

UPDATE: The Paradigm Research Group, one of the organizations sponsoring the petitions, has issued a statement saying, “As expected it was written by a low level staffer from the Office of Science and Technology Policy – research assistant Phil Larson. The response was unacceptable.”

See the petitions and the response at the WhiteHouse.gov website.

Hat Tip: NASA Watch

Posted on by Tammy Plotner

Naturally Occuring Complex Organic Material Is The By-Product Of Stars

We might think of most of the Universe as a vast, cold, uncaring place where elements rule… But we’d be wrong. Astronomers are now reporting that organic compounds of high diversity exist throughout the Cosmos and aren’t the primary property of life. Are we all just “star stuff”? You bet. Complex organic materials can be produced by stars!

While these complex compounds bear a resemblance to our Earthly coal and petroleum, they’re out there. Professor Sun Kwok and Dr. Yong Zhang of the University of Hong Kong have found that organic compounds exists throughout the Universe. These stellar by-products are mixture of aromatic (ring-like) and aliphatic (chain-like) components that closely resemble fossil fuels – a remnant of life. Does this raise eyebrows? Darn right it does. It means that “complex organic compounds can be synthesized in space even when no life forms are present.”

How did the team discover these organic compounds? During research, they found a bit of mystery – a set of unidentified infrared emissions in stars, galaxies and even interstellar space. For the last twenty years, this spectral signature has been commonly accepted as being PAHs – polycyclic aromatic hydrocarbon molecules. By utilizing the Infrared Space Observatory and the Spitzer Space Telescope, Kwok and Zhang have shown there’s more there than just a PAH… it’s a lot more complex. Through infra-red emissions and spectral studies, the team has shown that a nova event can produce these compounds in a very short period of time. It can happen within weeks.

Not only are the stars producing complex organic materials, but they’re pumping them into interstellar space as well. And the idea isn’t new. Kwok had proposed stars as compound factories and this current research supports his vision. “Our work has shown that stars have no problem making complex organic compounds under near-vacuum conditions,” says Kwok. “Theoretically, this is impossible, but observationally we can see it happening.”

But that’s not all. These types of complex materials are also found in meteorites. This opens the door to the theory that the early solar nebula may have also been home to organic materials. Could this be the “space seed” that began life on Earth? Just asking…

Original Story Source: Space Ref News Release.

Posted on by Tammy Plotner

Taking Mars’ Temperature – The ALH84001 Meteorite

This photograph shows globules of orange-colored carbonate minerals found in the Martian meteorite dubbed ALH84001. The origin of the carbonate minerals has long puzzled scientists, but by determining that the carbonate formed at about 18 degrees Celsius, Caltech researchers say they might have an answer. The mild temperature is also consistent with the theory that Mars was once warmer and wetter than it is today. Credit: NASA

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It might be four billion years old, but this meteorite which may have originated near the surface of Mars has a story to tell… one about a warmer and wetter history. Researchers at the California Institute of Technology (Caltech) have been analyzing the carbonate minerals contained within the Martian meteorite – ALH84001- and piecing together a climate history which showed the minerals formed at about 18 degrees Celsius (64 degrees Fahrenheit).

“The thing that’s really cool is that 18 degrees is not particularly cold nor particularly hot,” says Woody Fischer, assistant professor of geobiology and coauthor of the paper, published online in the Proceedings of the National Academy of Sciences (PNAS) on October 3. “It’s kind of a remarkable result.”

All recent studies, from rovers to spectroscopy, point to Mars having once had a much more temperate climate than its current average temperature of -63 degrees Celsius. Missions have photographed dry river beds, deltas, extinct lakes and more. Up until now, the one crucial point has been the lack of physical evidence. “There are all these ideas that have been developed about a warmer, wetter early Mars,” Fischer says. “But there’s precious little data that actually bears on it.” That is, until now.

Of course, this mineralogical evidence is strictly one point – but it’s one point closer to knowing the full score. “It’s proof that early in the history of Mars, at least one place on the planet was capable of keeping an Earth-like climate for at least a few hours to a few days,” says John Eiler, the Robert P. Sharp Professor of Geology and professor of geochemistry, and a coauthor of the paper. The first author is Itay Halevy, a former postdoctoral scholar who’s now at the Weizmann Institute of Science in Israel.

Where did this new evidence come from? Try ALH84001, a Martian meteorite discovered in 1984 in the Allan Hills of Antarctica. While scientists cannot definitely prove where it came from, ALH84001 is theorized to have once originated several hundred feet below the Martian surface and was blown Earthward during an impact event. The Martian meteorite made headlines in 1996 when little inclusions that appeared to be fossilized bacteria were discovered. Even though the thought of simple life forms were quickly shot down, the pockets which contained carbonate minerals remained an enigma.

“It’s been devilishly difficult to work out the process that generated the carbonate minerals in the first place,” Eiler says. But there have been countless hypotheses, he adds, and they all depend on the temperature in which the carbonates formed. Some scientists say the minerals formed when carbonate-rich magma cooled and crystallized. Others have suggested that the carbonates grew from chemical reactions in hydrothermal processes. Another idea is that the carbonates precipitated out of saline solutions. The temperatures required for all these processes range from above 700 degrees Celsius in the first case to below freezing in the last. “All of these ideas have merit,” Eiler says.

Deducing the temperature may help scientists to understand how the carbonates came to be, so a form of modeling called clumped-isotope thermometry was employed to help. It’s so sensitive it’s able to determine a dinosaur’s body temperature in relation to Earth’s climate history. In this case, the team measured concentrations of the rare isotopes oxygen-18 and carbon-13 contained in the carbonate samples. Carbonate is made out of carbon and oxygen, and as it forms, the two rare isotopes may bond to each other – clumping together, as Eiler calls it. As the temperature progressively lowers, the isotopes do their thing and clump. The degree to which this happens is directly related to temperature. The temperature the researchers measured – 18 ± 4 degrees Celsius – rules out many carbonate-formation hypotheses. “A lot of ideas that were out there are gone,” Eiler says. For one, the mild temperature means that the carbonate must have formed in liquid water. “You can’t grow carbonate minerals at 18 degrees other than from an aqueous solution,” he explains.

Through this new information, it is also hypothesized the minerals may have come into existence inside the cavities of rock while it was below ground. “As the water evaporated, the rock outgassed carbon dioxide, and the solutes in the water became more concentrated. The minerals then combined with dissolved carbonate ions to produce carbonate minerals, which were left behind as the water continued to evaporate.” A vessel for life? Well, chances aren’t good since any liquid water would have lasted for only a brief time – but it is a great indicator that this precious life-giver was once a part of Mars’ history.

Original Story Source: Caltech News Release.

Posted on by Ray Sanders

Even the Early Universe Had the Ingredients for Life

The optical image of TN J0924-2201, a very distant radio galaxy at (redshift) z = 5.19, obtained with the Hubble Space Telescope. (c) NASA/STScI/NAOJ.

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For us carbon-based life forms, carbon is a fairly important part of the chemical makeup of the Universe. However, carbon and oxygen were not created in the Big Bang, but rather much later in stars. How much later? In a surprising find, scientists have detected carbon much earlier in the Universe’s history than previously thought.

Researchers from Ehime University and Kyoto University have reported the detection of carbon emission lines in the most distant radio galaxy known. The research team used the Faint Object Camera and Spectrograph (FOCAS) on the Subaru Telescope to observe the radio galaxy TN J0924-2201. When the research team investigated the detected carbon line, they determined that significant amounts of carbon existed less than a billion years after the Big Bang.

How does this finding contribute to our understanding of the chemical evolution of the universe and the possibilities for life?

To understand the chemical evolution of our universe, we can start with the Big Bang. According to the Big Bang theory, our universe sprang into existence about 13.7 billion years ago. For the most part, only Hydrogen and Helium ( and a sprinkle of Lithium) existed.

So how do we end up with everything past the first three elements on the periodic table?

Simply put, we can thank previous generations of stars. Two methods of nucleosythesis (element creation) in the universe are via nuclear fusion inside stellar cores, and the supernovae that marked the end of many stars in our universe.

Over time, through the birth and death of several generations of stars, our universe became less “metal-poor” (Note: many astronomers refer to anything past Hydrogen and Helium as metals”). As previous generations of stars died out, they “enriched” other areas of space, allowing future star-forming regions to have conditions necessary to form non-star objects such as planets, asteroids, and comets. It is believed that by understanding how the universe created heavier elements, researchers will have a better understanding of how the universe evolved, as well as the sources of our carbon-based chemistry.

So how do astronomers study the chemical evolution of our universe?

By measuring the metallicity (abundance of elements past Hydrogen on the periodic table) of astronomical objects at various redshifts, researchers can essentially peer back into the history of our universe. When studied, redshifted galaxies show wavelengths that have been stretched (and reddened, hence the term redshift) due to the expansion of our universe. Galaxies with a higher redshift value (known as “z”) are more distant in time and space and provide researchers information about the metallicity of the early universe. Many early galaxies are studied in the radio portion of the electromagnetic spectrum, as well as infra-red and visual.

The research team from Kyoto University set out to study the metallicity of a radio galaxy at higher redshift than previous studies. In their previous studies, their findings suggested that the main era of increased metallicity occurred at higher redshifts, thus indicating the universe was “enriched” much earlier than previous believed. Based on the previous findings, the team then decided to focus their studies on galaxy TN J0924-2201 – the most distant radio galaxy known with a redshift of z = 5.19.

The deep optical spectrum of TN J0924-2201 obtained with FOCAS on the Subaru Telescope. The red arrows point to the carbon emission line.

The research team used the FOCAS instrument on the Subaru Telescope to obtain an optical spectrum of galaxy TN J0924-2201. While studying TN J0924-2201, the team detected, for the first time, a carbon emission line (See above). Based on the detection of the carbon emission line, the team discovered that TN J0924-2201 had already experienced significant chemical evolution at z > 5, thus an abundance of metals was already present in the ancient universe as far back as 12.5 billion years ago.

If you’d like to read the team’s findings you can access the paper Chemical properties in the most distant radio galaxy – Matsuoka, et al at: http://arxiv.org/abs/1107.5116

Source: NAOJ Press Release

Posted on by Ray Sanders

Martian Atmosphere Supersaturated with Water?

Artist's impression of the Mars Express spacecraft in orbit. Image Credit: ESA/Medialab

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Last week, scientists announced findings based on data from the SPICAM spectrometer onboard ESA’s Mars Express spacecraft. The findings reported in Science by Maltagliati et al (2011), reveal that the Martian atmosphere is supersaturated with water vapor. According to the research team, the discovery provides new information which will help scientists better understand the water cycle and atmospheric history of Mars.

What processes are at work to allow large amounts of water vapor in the Martian atmosphere?

The animated sequence to the left shows the water cycle of the Martian atmosphere in action:

When the polar caps of Mars (which contain frozen Water and CO2) are warmed by the Sun during spring and summer, the water sublimates and is released into the atmosphere.

Atmospheric winds transport the water vapor molecules to higher altitudes. When the water molecules combine with dust molecules, clouds are formed. If there isn’t much dust in the atmosphere, the rate of condensation is reduced, which leaves water vapor in the atmosphere, creating a supersaturated state.

Water vapor may also be transported by wind to the southern hemisphere or may be carried high in the atmosphere.In the upper atmosphere the water vapor can be affected by photodissociation in which solar radiation (white arrows) splits the water molecules into hydrogen and oxygen atoms, which then escape into space.

Scientists had generally assumed that supersaturation cannot exist in the cold Martian atmosphere, believing that any water vapor in excess of saturation instantly froze. Data from SPICAM revealed that supersaturation takes place at altitudes of up to 50 km above the surface when Mars is at its farthest point from the Sun.

Based on the SPICAM data, scientists have learned that there is more water vapor in the Martian atmosphere than previously believed. While the amount of water in Mars’ atmosphere is about 10,000 times less water vapor than that of Earth, previous models have underestimated the amount of water in the Martian atmosphere at altitudes of 20-50km, as the data suggests 10 to 100 times more water than expected at said altitudes.

“The vertical distribution of water vapour is a key factor in the study of Mars’ hydrological cycle, and the old paradigm that it is mainly controlled by saturation physics now needs to be revised,” said Luca Maltagliati, one of the authors of the paper. “Our finding has major implications for understanding the planet’s global climate and the transport of water from one hemisphere to the other.”

“The data suggest that much more water vapour is being carried high enough in the atmosphere to be affected by photodissociation,” added Franck Montmessin, Principal Investigator for SPICAM and co-author of the paper.

“Solar radiation can split the water molecules into oxygen and hydrogen atoms, which can then escape into space. This has implications for the rate at which water has been lost from the planet and for the long-term evolution of the Martian surface and atmosphere.”

However, water vapour is a very dynamic trace gas, and one of the most seasonally variable atmospheric constituents on Mars.

Source: ESA/Mars Express Mission Updates

Posted on by Ray Sanders

Citizen Science: Help Find Life on Mars

This photo was taken by a DeepWorker submersible in Kelly Lake. Credit: NASA

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Interested in helping NASA scientists pinpoint where to look for signs of life on Mars?

If so, you can join a new citizen science website called MAPPER, launched in conjunction with the Pavilion Lake Research Project’s 2011 field season.

How can the MAPPER and Pavilion Lake Research projects help scientists look for off-Earth life?

Since 2008, the Pavilion Lake Research Project (PLRP) has used DeepWorker submersible vehicles to investigate the underwater environment of two lakes in Canada (Pavilion and Kelly). With the MAPPER project, citizen scientists can work with NASA scientists and explore the lake bottoms from the view of a DeepWorker pilot.

The PLRP team’s main area of focus are freshwater carbonate formations known as microbialites. By studying microbialites that thrive in Pavilion and Kelly Lake, the scientists believe a better understanding of how the formations develop. Through a greater understanding of the carbonate formations, the team believes they will gain deeper insights into where signs of life may be found on Mars and beyond.

To investigate the formations in detail, video footage and photos of the lake bottom are recorded by DeepWorker sub pilots. The data requires analysis in order to determine what types of features can be found in different parts of the lake. Analyzing the data allows the team to answer questions such as; “how does microbialite texture and size vary with depth?” and “why do microbialites grow in certain parts of the lake but not in others?”.

The amount of data to analyze is staggering – if each image taken were to be printed, the stack would be taller than the depth of Pavilion Lake (over 60 meters). If each image were reviewed one-by-one, the PLRP’s team would never be able to complete their work. Distributing the work to the general public solves the problem, due in part by spreading the massive work out over many volunteers across the Internet.

Since the PLRP 2011 field season Morphology Analysis Project for Participatory Exploration and Research (MAPPER) MAPPER has been open to the general public. By opening MAPPER to the public, anyone can explore Pavilion and Kelly Lake as full-fledged members of PLRP’s Remote Science Team.

So how do volunteers use MAPPER to help the PLRP team?

Once volunteers create an account at: getmapper.com, the volunteers complete a brief tutorial, which provides the necessary training to tag photos in the PLRP dataset. MAPPER has ease-of-use in mind, providing users with a simple interface, which makes tagging features like sediment, microbialites, rocks, and algae easy. In case a user is unsure of how to tag a photo, examples and descriptions of each feature are available.

Screenshot of Mapper in action. Image Credit: NASA

In a manner similar to online games, each photo tagged earns the volunteer points which can be used to unlock new activities. Volunteers can also compete with other Remote Science Team members on the MAPPER leaderboard. Volunteers can also check to see how close each dataset is to being completely reviewed and see how much they have contributed to said dataset, as well as seeing what features have been tagged the most. Volunteers who tag a photo as ‘cool’ save said image to their Cool Photos album, allowing them to easily find the image at a later date.

PLRP Remote Science Team members from across North America, Europe and Asia have already been making discoveries in Pavilion and Kelly Lake. If you’d like to become a PLRP Remote Science Team member, visit: www.getmapper.com
You can also learn more by visiting the MAPPER Facebook page