This water could be some of the oldest on the planet and may even contain life. Not just that, but the similarity between the rocks that trapped it and those on Mars raises the hope that comparable life-sustaining water could lie buried beneath the red planet's surface.

The findings, published in Nature, may force us to rethink which parts of our planet are fit for life, and could reveal clues about how microbes evolve in isolation.

Researchers from the universities of Manchester, Lancaster, Toronto and McMaster analysed water pouring out of boreholes from a mine 2.4 kilometres beneath Ontario, Canada.

They found that the water is rich in dissolved gases like hydrogen, methane and different forms - called isotopes - of noble gases such as helium, neon, argon and xenon. Indeed, there is as much hydrogen in the water as around hydrothermal vents in the deep ocean, many of which teem with microscopic life.

The hydrogen and methane come from the interaction between the rock and water, as well as natural radioactive elements in the rock reacting with the water. These gases could provide energy for microbes that may not have been exposed to the sun for billions of years.

The crystalline rocks surrounding the water are thought to be around 2.7 billion years old. But no-one thought the water could be the same age, until now.

Using ground-breaking techniques developed at the University of Manchester, the researchers show that the fluid is at least 1.5 billion years old, but could be significantly older.

NERC-funded Professor Chris Ballentine of the University of Manchester, co-author of the study, and project director, says: 'We've found an interconnected fluid system in the deep Canadian crystalline basement that is billions of years old, and capable of supporting life. Our finding is of huge interest to researchers who want to understand how microbes evolve in isolation, and is central to the whole question of the origin of life, the sustainability of life, and life in extreme environments and on other planets.'

Before this finding, the only water of this age was found trapped in tiny bubbles in rock and is incapable of supporting life. But the water found in the Canadian mine pours from the rock at a rate of nearly two litres per minute. It has similar characteristics to far younger water flowing from a mine 2.8 kilometres below ground in South Africa that was previously found to support microbes.

Ballentine and his colleagues don't yet know if the underground system in Canada sustains life, but Dr Greg Holland of Lancaster University, lead author of the study says: 'Our Canadian colleagues are trying to find out if the water contains life right now. What we can be sure of is that we have identified a way in which planets can create and preserve an environment friendly to microbial life for billions of years. This is regardless of how inhospitable the surface might be, opening up the possibility of similar environments in the subsurface of Mars.'

Professor Ballentine, based in Manchester's School of Earth, Atmospheric and Environmental Sciences, adds: 'While the questions about life on Mars raised by our work are incredibly exciting, the ground-breaking techniques we have developed at Manchester to date ancient waters also provide a way to calculate how fast methane gas is produced in ancient rock systems globally. The same new techniques can be applied to characterise old, deep groundwater that may be a safe place to inject carbon dioxide.'

David Willetts, Minister for Universities and Science, says: 'This is excellent pioneering research. It gives new insight into our planet. It has also developed new technology for carbon capture and storage projects. These have the potential for growth, job creation and our environment.'

The paper - Deep fracture fluids isolated in the crust since the Precambrian era by G. Holland, B. Sherwood Lollar, L. Li, G. Lacrampe-Couloume, G. F. Slater and C. J. Ballentine, in Nature - will be published online on 16 May 2013

]]> Mon, 20 MAY 2013 12:29:39 AEST Moffett Field CA (SPX) May 03, 2013 - At this early stage in the search for extraterrestrial life in our solar system and beyond, the emphasis is on liquid water. Where it can exist on a planet's or moon's surface, so the thinking goes, life as we know it has a chance.

Much of the observational and theoretical work in astrobiology therefore concerns the "habitable zone," the orbital band around stars where a rocky world's water neither freezes away nor boils off.

In a new contribution to this effort, a recent study has looked at a little-explored influencer on the ability of water to remain liquid on a world's surface: atmospheric pressure.

"Atmospheric pressure affects the liquid water temperature range that is commonly used to define planetary habitability," said Giovanni Vladilo of the Trieste Astronomical Observatory in Italy and lead author of the paper published in the Astrophysical Journal.

"So, if you wish to estimate habitability, you should explicitly take into account pressure in your problem."

On Earth, the space around us is filled with air molecules that collectively weigh on our bodies. Although you cannot feel it, Earth's atmosphere presses down with the force of one kilogram per square centimeter, or 14.7 pounds per square inch.

That pressure works out to about a ton per square foot. Our terrestrial biology evolved to operate in this pressure, which, while startling-sounding, pales when compared to underwater creatures' bodies in the deep sea that can withstand dozens of tons per square foot.

Atmospheric pressure has an impact on water's boiling point when it transitions from a liquid to a gas. As anyone who has cooked at high altitudes has experienced, water boils there at a lower temperature than the typical 100 degrees Celsius (212 degrees Fahrenheit).

The reason: Atmospheric pressure is lower at high altitudes than at sea level; there is simply less atmosphere pressing down the higher you go up in the mountains. Lower pressure is why it takes a few minutes longer to make pasta in mile-high Denver than below-sea-level New Orleans-the pasta has to soak and soften in the water longer to become al dente in Denver because the water is boiling at a slightly lower temperature.

Vladilo explained why pressure has this effect. "Temperature is an indicator of the speed of molecular motions. The boiling point occurs when molecular motions are sufficiently fast to allow most molecules to escape from each other," and thus turn into gas, he said. "Pressure keeps molecules tight, so the higher the pressure, the faster the molecules must move-that is, the higher the temperature must be-for evaporation to occur."

Like Earth, give or take an atmosphere
In Vladilo's new paper, he and his colleagues modeled a planet just like Earth in size and atmospheric composition. They ran over 4,000 computer simulations that varied the model planet's atmospheric pressure from one-hundredth to six times the atmospheric pressure of Earth.

The researchers also varied the virtual planet's orbital distance from its Sun-like star from about two-thirds of the Earth-Sun distance to around an additional third. To get a sense of these orbital parameters, the former is a bit tighter than Venus and the latter more than half the distance out to Mars.

The researchers' model estimated the global habitability of these Earth-like exoplanets by gauging the extent of the planet's latitudes that could possess liquid surface water.

Through their modeling, Vladilo and colleagues saw that the habitable zone expanded in width as the atmospheric pressure increased. At a tenth of Earth's atmospheric pressure, the outer edge of the habitable zone reached just two percent farther out than Earth; not a lot of wiggle room for a low-pressure, Earth-like world, in other words, when it comes to habitability. But as the atmospheric pressure increased to threefold that of Earth's, the habitable zone extended out a farther 18 percent.

For the same pressure interval, low-to-high, the inner edge of the habitable zone ranged from 87 percent of the Earth-Sun distance to 77 percent. In this model, for a planet with Earth's atmospheric pressure, cloudiness, and humidity, the inner edge of the habitable zone is smack dab in the middle of this range, at 82 percent of the Earth-Sun distance.

The results indicate that an exoplanet just like Earth in all other respects but with a higher atmospheric pressure could be considered habitable about five percent closer to its Sun-like star. Conversely, a low-pressure Earth would not be considered habitable unless placed in an orbit five percent farther out than a standard-pressure Earth.

The movement of heat
A main factor behind the expanded orbital range of habitability at higher pressures is that higher pressure atmospheres are denser. Denser atmospheres, in turn, transport heat better than thin atmospheres, and promote a stronger "greenhouse effect", whereby atmospheric gases absorb heat.

For exoplanets farther from their star than Earth is from our sun, and therefore receive less sunlight, a high-pressure atmosphere traps heat better and distributes the greater warmth received at the equator. Polar zones that would otherwise freeze instead retain liquid water. A high-pressure planet can remain warmer at farther distances from its star accordingly.

With regards to low-pressure worlds - hearkening back to the pasta cooking analogy - water boils at lower temperatures than it does on higher atmospheric pressure worlds. In a low-pressure scenario, a world closer to its star than Earth that would otherwise be broadly habitable with Earth's atmospheric pressure would have its water boil off.

For closer-in exoplanets with a high atmospheric pressure, however, the sun-scorched equatorial zones would not heat to a boiling level as readily as in a normal- or low-pressure situation, and thus could still be habitable.

What might live there
In addition to these general findings, the researchers' model offers intriguing insights. For example, much of the gain in survivability on the closer-to-the-star side of the habitable zone for high-pressure worlds is for organisms that, at least by our Earthly standards, are extreme.

The global temperatures on these inner-edge worlds made habitable by their high atmospheric pressures would be too high for complex life forms such as ourselves. So-called thermophiles, however - bacteria that thrive at temperatures more than 45 degrees Celsius (113 degrees Fahrenheit) or so and on up to considerably higher temperatures - might find such heat-blasted worlds quite comfortable.

Overall, the habitable zone for creatures like us that require relatively moderate temperatures actually moves outward somewhat from a Sun-like star in high-pressure scenarios.

Atmospheric pressure could also have a profound effect on biodiversity. Compared to low-pressure worlds, high-atmospheric pressure exoplanets would have rather uniform global surface temperatures, again owing to the efficient transfer of heat amongst their latitudes. These heavy-atmosphere planets might host a fairly narrow range of life forms, since all would be adapted to the same slim temperature regime.

Planets with lower atmospheric pressures than Earth, though, would have even more varied temperatures than our planet. These abodes might then provide an even wider range of habitats than our world, with organisms exotically adapted to their considerably more intensely varied polar-temperate-tropical bands.

Whence atmospheres?
For now, research on a "pressure-dependent habitable zone" is somewhat purely academic, given that atmospheric pressure is not a property of exoplanets that we can yet measure. But Vladilo believes that work with planets several times larger than Earth, dubbed super-Earths, could be where the atmospheric pressure insights are first able to be applied.

"At the present time, observations are able to determine only a few properties of planetary atmospheres, such as their chemical composition, and mostly for giant planets rather than terrestrial ones," Vladilo said.

"However, I'm confident that technological improvements will allow us to characterize, to some extent, the atmospheres of super-Earths, which are reasonable candidates for studies of planetary habitability.

"If we will be able to estimate some basic planet parameters with observations, such as the planetary albedo [the amount of light reflected by the surface] and infrared flux [the amount of infrared light emitted], then our models will be sufficiently constrained to yield a reasonable estimate of the planet surface pressure."

A major issue for assessing exoplanetary atmospheric pressures is the fact that the formation of atmospheres and the densities they develop is not well understood.

Saturn's moon Titan, for instance, has a thick atmosphere with a pressure about 50 percent greater than that of Earth's. Yet similar bodies in the outer solar system, such as Jupiter's moons Ganymede and Callisto, cling to only very tenuous envelopes of gas.

"It's embarrassing that we have almost no idea of atmospheres and where they come from," said Sara Seager, a professor of planetary science and physics at the Massachusetts Institute of Technology who was not involved in the new study. "It's one of those thing we can hope and wait to learn about."

With regards to Vladilo's research, Seager said "it's refreshing to see that a wide range of surface pressures could enable a habitable surface."

Vladilo and his colleagues plan a number of follow-ups with their model. Other subtle aspects of exoplanetary habitability remain to be examined in the ever-expanding scientific literature that matches the growing excitement for possibly detecting alien life in the near future.

Said MIT's Seager: "The uptick in papers on planetary habitability is a telling sign of what's to come."

]]> Mon, 20 MAY 2013 12:29:39 AEST Frankfurt, Germany (SPX) Apr 26, 2013 - Lichens are symbiotic organisms consisting of a fungal partner and one or several algal partners. The association is so close that scientists until 1867 were not aware that lichens actually consist of two different partners.

After the Swiss botanist Simon Schwendener discovered the dual nature of lichens, lichenologists were focusing on the fungal partner when studying lichens, since it was often believed that only few algae are involved in the symbiosis.

Molecular studies have shown that it was a mistake to neglect the algal partner for a long time. The diversity of algal partners have been shown to be much higher than expected. In addition the study by Dr. Christian Printzen, Senckenberg Research Institute (Frankfurt), and his colleagues in Frankfurt and Madrid has shown that, by choosing different algal partners, lichen fungi are able to colonize different ecosystems.

The study focuses on the Spiny Heath Lichen (Cetraria aculeata), which has a peculiar distribution range. It belongs to the so-called bipolar species that occur in polar and alpine regions of the northern and southern Hemisphere.

However, this species also occurs in the climatically different Mediterranean region with dry steppe-like vegetation. Dr. Printzen's studies now show that this distribution can be explained by the presence of different algal species in the polar vs. Mediterranean populations.

The paper, published in the open access journal Mycokeys, discusses the genetic differences of these algae and their evolutionary and ecological implications. "It is an example how molecular techniques in tandem with ecophysiological studies can enhance our knowledge of the biology of this fascinating type of symbiosis.", comments Dr. Christian Printzen the lead author of the study.

Printzen C, Domaschke S, Fernandez-Mendoza F, Perez-Ortega S (2012) Biogeography and ecology of Cetraria aculeata, a widely distributed lichen with a bipolar distribution. In: Kansri Boonpragob, Peter Crittenden, H.Thorsten Lumbsch (Eds) Lichens: from genome to ecosystems in a changing world.MycoKeys 6: 33, doi: 10.3897/mycokeys.6.3185.

]]> Mon, 20 MAY 2013 12:29:39 AEST San Francisco CA (SPX) Apr 25, 2013 - NASA's Kepler mission has discovered a new planetary system that is home to five small planets around a slightly smaller star than our Sun. Two of them are super-Earth planets, most likely made of rock or ice mixed with rock, which are located in the habitable zone of their host star. This discovery is providing a target for the SETI search, since if life has thrived on these worlds and reached a point where civilization has developed complex technology, it may be detectable.

When the NASA Kepler mission was launched on March 9, 2007, the Delta II rocket was carrying the hope of a large community of scientists who dedicate their work to studying extra-solar planets, planets in orbit around other stars. The Kepler mission's main scientific objective is exploration of the structure and diversity of planetary systems. It accomplishes this goal by staring almost constantly at a large field composed of about 150,000 stars to detect small dips in brightness due to the transits of a planet.

Kepler has already been a successful NASA mission with the discovery of 2,740 planet candidates with estimated sizes from Mercury to larger than Jupiter. A fifth of these planet candidates are also called "super-Earths," a new class of planets, without analog in our solar system, with a radius between 1.25 to 2 times the radius of our planet.

Today, in a scientific article published in Science magazine and through a NASA press conference, the Kepler team announced the discovery of a multiple planet system, composed of 5 Earth-sized and super-Earth planets orbiting a K-type star.

The detection of these planets was indirect since Kepler astronomers observed the attenuation of the host star's brightness due to the passage of a planet in the line of sight, and not the planets themselves. The authenticity of this multiple planet system was confirmed by a statistical analysis based on previous detections of multiple planets by Kepler.

"By estimating the rate of false-positives due the remote possibility of additional planet-hosting stars in the photometric aperture we have strong confidence that we have discovered two genuine transiting super-Earth planets in the habitable zone of their host star. Such calculations are only possible because of the thousands of additional transiting extrasolar planets that Kepler has discovered" said Jason Rowe, Research Scientist at the Carl Sagan Center of the SETI Institute and co-author of the work

The outermost planet, named Kepler-62f (radius about 1.4 times Earth's radius and a period of 267 Earth days) is located in the habitable zone of the star, a region around the star where a rocky planet with an atmosphere similar to Earth could host liquid water on its surface.

The team expanded the definition of the Habitable Zone by taking into account the evolution of the brightness of the host star. Their calculations suggest that Kepler-62e (radius about 1.6 times Earth's radius and a period of 122 Earth days) was also in the habitable zone so that liquid water could have existed on its surface, too.

Similar to Venus and Mars that are believed to have lost their surface water 1 billion years and 3.8 billion years ago respectively, before our Sun was more luminous, the host star's habitable zone was broader in the past. The Kepler team's calculations suggest that Kepler-62e (radius about 1.6 times Earth's radius and a period of 122 Earth days) is also in the habitable zone so that liquid water could exist on its surface, too.

"These discoveries move us farther down the road to discovering planets similar to Earth. While we don't know if Kepler-62e and f are rocky or whether they have liquid water pooling on their surfaces, their existence shows that the incidence of small worlds in the habitable zone of Sun-like stars is high.

Thus we can look forward to the discovery and detailed characterization of Earth's cousins in the years and decades to come by future missions and telescopes." said Jon Jenkins Senior Scientist at the Carl Sagan Center of the SETI Institute and also co-author of the work.

Both Goldilocks planets' masses remain unknown since they are too small to produce detectable gravitational effects on the host star and between themselves. However, considering a lower upper limit for their mass and the age of the star, estimated to be 7 billion years, the team suggests that both planets are solid and either made of a dry rocky material, like Earth, or a large body of water surrounding a core of iron and rock (a water world).

Kepler discoveries are an amazing opportunity to focus the search for technosignatures conducted at the Center for SETI Research led by Gerry Harp. Kepler provides the detection of exoworlds that could host water on their surfaces and potentially life. Unfortunately, the planets of the Kepler-62 system are too distant (850 light-years from Earth) to be fully characterized, and no direct measurement of their atmospheric composition is possible with current technologies.

"Since December of 2011, the SonATA program to search for extraterrestrial intelligence with the Allen Telescope Array has been focusing on the Kepler exoplanet candidates and especially those planets expected to be within the "Habitable Zone" of their stars.

"Our surveys improve on previous, generally narrowband SETI by covering the radio frequency range where Earth's atmosphere is most transparent, including many frequencies never before observed. We expect to complete a meaningful survey of these stars in less than 1 year -- be sure to check back soon." says Gerry Harp, Director of the Center for SETI Research.

]]> Mon, 20 MAY 2013 12:29:39 AEST Antioquia, Colombia (UPI) Apr 17, 2013 - Some Earth-like exoplanets that are seemingly habitable may be missing magnetic shielding, exposing them to damaging radiation, researchers in Colombia say.

To support life as we know it, planets need thick, water-rich atmospheres and liquid surface water, Jorge Zuluaga at the University of Antioquia and colleagues said, but water can get blasted away by stellar winds unless the planet has a strong magnetic field.

In our own solar system Mars and Venus do not have magnetic fields, and it is thought stellar winds stripped away the bulk of Mars's atmosphere while Venus was left with one of mostly carbon dioxide, making it toxic, they said.

In most planets it is a churning molten core that generates a magnetic field, so the researchers calculated how long it would take a rocky, Earth-like planet to cool to the point that it's internal magnetic generator stopped working, NewScientist.com reported Wednesday.

They applied their calculations three well-known exoplanets considered to be potentially habitable: Gliese 581d, HD 40307g and GJ 667Cc.

The first two might have magnetic fields just barely strong enough to protect the planets from dangerous stellar radiation, they said, but the third is doomed.

The presence or absence of magnetic fields needs to be taken into account when considering whether a planet might be capable of supporting life, Zuluaga said.

]]> Mon, 20 MAY 2013 12:29:39 AEST Boston MA (SPX) Apr 19, 2013 - An international team of researchers has decoded the genome of a creature whose evolutionary history is both enigmatic and illuminating: the African coelacanth. A sea-cave dwelling, five-foot long fish with limb-like fins, the coelacanth was once thought to be extinct.

A living coelacanth was discovered off the African coast in 1938, and since then, questions about these ancient-looking fish - popularly known as "living fossils" - have loomed large. Coelacanths today closely resemble the fossilized skeletons of their more than 300-million-year-old ancestors. Its genome confirms what many researchers had long suspected: genes in coelacanths are evolving more slowly than in other organisms.

"We found that the genes overall are evolving significantly slower than in every other fish and land vertebrate that we looked at," said Jessica Alfoldi, a research scientist at the Broad Institute and co-first author of a paper on the coelacanth genome, which appears in Nature this week. "This is the first time that we've had a big enough gene set to really see that."

Researchers hypothesize that this slow rate of change may be because coelacanths simply have not needed to change: they live primarily off of the Eastern African coast (a second coelacanth species lives off the coast of Indonesia), at ocean depths where relatively little has changed over the millennia.

"We often talk about how species have changed over time," said Kerstin Lindblad-Toh, scientific director of the Broad Institute's vertebrate genome biology group and senior author. "But there are still a few places on Earth where organisms don't have to change, and this is one of them. Coelacanths are likely very specialized to such a specific, non-changing, extreme environment - it is ideally suited to the deep sea just the way it is."

Because of their resemblance to fossils dating back millions of years, coelacanths today are often referred to as "living fossils" - a term coined by Charles Darwin. But the coelacanth is not a relic of the past brought back to life: it is a species that has survived, reproduced, but changed very little in appearance for millions of years. "It's not a living fossil; it's a living organism," said Alfoldi. "It doesn't live in a time bubble; it lives in our world, which is why it's so fascinating to find out that its genes are evolving more slowly than ours."

The coelacanth genome has also allowed scientists to test other long-debated questions. For example, coelacanths possess some features that look oddly similar to those seen only in animals that dwell on land, including "lobed" fins, which resemble the limbs of four-legged land animals (known as tetrapods). Another odd-looking group of fish known as lungfish possesses lobed fins too. It is likely that one of the ancestral lobed-finned fish species gave rise to the first four-legged amphibious creatures to climb out of the water and up on to land, but until now, researchers could not determine which of the two is the more likely candidate.

In addition to sequencing the full genome - nearly 3 billion "letters" of DNA - from the coelacanth, the researchers also looked at RNA content from coelacanth (both the African and Indonesian species) and from the lungfish. This information allowed them to compare genes in use in the brain, kidneys, liver, spleen and gut of lungfish with gene sets from coelacanth and 20 other vertebrate species. Their results suggested that tetrapods are more closely related to lungfish than to the coelacanth.

However, the coelacanth is still a critical organism to study in order to understand what is often called the water-to-land transition. Lungfish may be more closely related to land animals, but its genome remains inscrutable: at 100 billion letters in length, the lungfish genome is simply too unwieldy for scientists to sequence, assemble, and analyze. The coelacanth's more modest-sized genome (comparable in length to our own) is yielding valuable clues about the genetic changes that may have allowed tetrapods to flourish on land.

By looking at what genes were lost when vertebrates came on land as well as what regulatory elements - parts of the genome that govern where, when, and to what degree genes are active - were gained, the researchers made several unusual discoveries:

+ Sense of smell. The team found that many regulatory changes influenced genes involved in smell perception and detecting airborne odors. They hypothesize that as creatures moved from sea to land, they needed new means of detecting chemicals in the environment around them.

+ Immunity. The researchers found a significant number of immune-related regulatory changes when they compared the coelacanth genome to the genomes of animals on land. They hypothesized that these changes may be part of a response to new pathogens encountered on land.

+ Evolutionary development. Researchers found several key genetic regions that may have been "evolutionarily recruited" to form tetrapod innovations such as limbs, fingers and toes, and the mammalian placenta. One of these regions, known as HoxD, harbors a particular sequence that is shared across coelacanths and tetrapods. It is likely that this sequence from the coelacanth was co-opted by tetrapods to help form hands and feet.

+ Urea cycle. Fish get rid of nitrogen by excreting ammonia into the water, but humans and other land animals quickly convert ammonia into less toxic urea using the urea cycle. Researchers found that the most important gene involved in this cycle has been modified in tetrapods.

The coelacanth genome may hold other clues for researchers investigating the evolution of tetrapods.

"This is just the beginning of many analyses on what the coelacanth can teach us about the emergence of land vertebrates, including humans, and, combined with modern empirical approaches, can lend insights into the mechanisms that have contributed to major evolutionary innovations," said Chris Amemiya, a member of the Benaroya Research Institute and co-first author of the Nature paper. Amemiya is also a professor at the University of Washington.

Sequencing the full coelacanth genome was uniquely challenging for many reasons. Coelacanths are an endangered species, meaning that samples available for research are almost nonexistent. This meant that each sample obtained was precious: researchers would have "one shot" at sequencing the collected genetic material, according to Alfoldi. But the difficulties in obtaining a sample and the challenges of sequencing it also knit the community together.

"The international nature of the work, its evolutionary value and history, and the fact that it was a technically challenging project really brought people together," said Lindblad-Toh. " We had representatives from every populated continent on earth working on this project."

Although its genome offers some tantalizing answers, the research team anticipates that further study of the fish's immunity, respiration, physiology, and more will lead to deep insights into how some vertebrates adapted to life on land, while others remained creatures of the sea.

Researchers from 40 institutions across 12 countries contributed to this work. Many funding agencies around the world provided support, including the African Coelacanth Ecosystem Programme of the South African National Department of Science and Technology, which supported the collection of samples, and the National Human Genome Research Institute, which supported the Broad Institute's contributions including genome sequencing. Paper cited: Amemiya, CT et al. "The African coelacanth genome provides insights into tetrapod evolution" Nature DOI: 10.1038/nature12027

]]> Mon, 20 MAY 2013 12:29:39 AEST Leeds UK (SPX) Apr 05, 2013 - Researchers at the University of Leeds may have solved a key puzzle about how objects from space could have kindled life on Earth. While it is generally accepted that some important ingredients for life came from meteorites bombarding the early Earth, scientists have not been able to explain how that inanimate rock transformed into the building blocks of life.

This new study shows how a chemical, similar to one now found in all living cells and vital for generating the energy that makes something alive, could have been created when meteorites containing phosphorus minerals landed in hot, acidic pools of liquids around volcanoes, which were likely to have been common across the early Earth.

"The mystery of how living organisms sprung out of lifeless rock has long puzzled scientists, but we think that the unusual phosphorus chemicals we found could be a precursor to the batteries that now power all life on Earth. But the fact that it developed simply, in conditions similar to the early Earth, suggests this could be University of Leeds
between geology and biology," said Dr Terry Kee, from the University's School of Chemistry, who led the research.

All life on Earth is powered by a process called chemiosmosis, where the chemical adenosine triphosphate (ATP), the rechargeable chemical 'battery' for life, is both broken down and re-formed during respiration to release energy used to drive the reactions of life, or metabolism. The complex enzymes required for both the creation and break down of ATP are unlikely to have existed on the Earth during the period when life first developed. This led scientists to look for a more basic chemical with similar properties to ATP, but that does not require enzymes to transfer energy.

Phosphorus is the key element in ATP, and other fundamental building blocks of life like DNA, but the form it commonly takes on Earth, phosphorus (V), is largely insoluble in water and has a low chemical reactivity. The early Earth, however, was regularly bombarded by meteorites and interstellar dust rich in exotic minerals, including the far more reactive form of phosphorus, the iron-nickel-phosphorus mineral schreibersite.

The scientists simulated the impact of such a meteorite with the hot, volcanically-active, early Earth by placing samples of the Sikhote-Alin meteorite, an iron meteorite which fell in Siberia in 1947, in acid taken from the Hveradalur geothermal area in Iceland. The rock was left to react with the acidic fluid in test tubes incubated by the surrounding hot spring for four days, followed by a further 30 days at room temperature.

In their analysis of the resulting solution the scientists found the compound pyrophosphite, a molecular 'cousin' of pyrophosphate - the part of ATP responsible for energy transfer. The scientists believe this compound could have acted as an earlier form of ATP in what they have dubbed 'chemical life'.

"Chemical life would have been the intermediary step between inorganic rock and the very first living biological cell. You could think of chemical life as a machine -a robot, for example, is capable of moving and reacting to surroundings, but it is not alive. With the aid of these primitive batteries, chemicals became organised in such a way as to be capable of more complex behaviour and would have eventually developed into the living biological structures we see today," said Dr Terry Kee.

The team from NASA's Jet Propulsion Laboratory (JPL-Caltech) working on the Curiosity rover, which landed on Mars in August last year, has recently reported the presence of phosphorus on the Red Planet.

"If Curiosity has found phosphorus in one of the forms we produced in Iceland, this may indicate that conditions on Mars were at one point suitable for the development of life in much the same way we now believe it developed on Earth," added Dr Kee.

The team at Leeds are now working with colleagues at JPL-Caltech to understand how these early batteries and the 'chemical life' they became part of might have developed into biological life. As part of this work they will be using facilities in the University of Leeds' Faculty of Engineering, currently used to test new fuel cells, to build a 'geological fuel cell' using minerals and gases common on the early Earth. Researchers will apply different chemicals to its surface and monitor the reactions take place and the chemical products which develop.

The team also hope to travel to Disko Island in Greenland which is home to the Earth's only naturally-occurring source of schreibersite, the mineral found in the Sikhote-Alin meteorite. Here, they hope to repeat their experiments and show that the same chemicals develop in an entirely Earth-originated setting.

The paper Hydrothermal modification of the Sikhote-Alin iron meteorite under low pH geothermal environments. A plausibly prebiotic route to activated phosphorus on the early Earth was published online by the journal Geochimica et Cosmochimica Acta on 15th March 2013. David E. Bryant, David Greenfield, Richard D. Walshaw, Benjamin R.G. Johnson, Barry Herschy, Caroline Smith, Matthew A. Pasek, Richard Telford, Ian Scowen, Tasnim Munshi, Howell G.M. Edwards, Claire R. Cousins, Ian A. Crawford, Terence P. Kee, Hydrothermal modification of the Sikhote-Alin iron meteorite under low pH geothermal environments.

]]> Mon, 20 MAY 2013 12:29:39 AEST Knoxville TN (SPX) Mar 29, 2013 - Beneath the ocean floor is a desolate place with no oxygen and sunlight. Yet microbes have thrived in this environment for millions of years. Scientists have puzzled over how these microbes survive, but today there are more answers.

A study led by Karen Lloyd, a University of Tennessee, Knoxville, assistant professor of microbiology, reveals that these microscopic life-forms called archaea slowly eat tiny bits of protein. The study was released today in Nature.

The finding has implications for understanding the bare minimum conditions needed to support life.

"Subseafloor microbes are some of the most common organisms on earth," said Lloyd. "There are more of them than there are stars or sand grains. If you go to a mud flat and stick your toes into the squishy mud, you're touching these archaea. Even though they've literally been right under our noses for all of human history, we've never known what they're doing down there."

Archaea are one of three life forms on earth, including bacteria and eukarya cells.

Scientists are interested in archaea's extreme way of life because it provides clues about the absolute minimum conditions required to sustain life as well as the global carbon cycle.

"Scientists had previously thought that proteins were only broken down in the sea by bacteria," said Lloyd. "But archaea have now turned out to be important new key organisms in protein degradation in the seabed."

Proteins make up a large part of the organic matter in the seabed, the world's largest deposit of organic carbon.

To reveal the cells' identities and way of life, Lloyd and her colleagues collected ocean mud containing the archaea cells from Aarhus Bay, Denmark. Then they pulled out four individual cells and sequenced their genomic DNA to discover the presence of the extracellular protein-degrading enzymes predicted in those genomes.

"We were able to go back to the mud and directly measure the activity of these predicted enzymes," said Andrew Steen, another UT researcher and coauthor of the study. "I was shocked at how high the activities were."

This novel method opens the door for new studies by microbiologists. Scientists have been unable to grow archaea in the laboratory, limiting their studies to less than one percent of microorganisms. This new method allows scientists to study microorganisms directly from nature, opening up the remaining 99 percent to research.

Lloyd collaborated with other researchers from UT, as well as, Aarhus University in Denmark, Bigelow Laboratory for Ocean Sciences in Maine, Ribocon GmbH in Germany, and the Max Planck Institute for Marine Biology in Germany.

]]> Mon, 20 MAY 2013 12:29:39 AEST Moffett Field CA (SPX) Mar 25, 2013

- On Tuesday March 13, NASA's Curiosity science team announced that the Martian rover had found the first confirmed site other than Earth where conditions were right to have once hosted ancient life, if it ever evolved on the red planet.

John Grotzinger, project scientist for the Curiosity mission, offered his perspective on the rover's journey of exploration and the historic find at the John Klein drill site.

A lot has happened in the seven months since Curiosity has landed. How does it feel to have accomplished so much in that time?

It feels terrific. I think our team has a really strong feeling of accomplishment. Everybody's worked really hard. We had a year of preparation for surface operations. Before we landed, we were able to get the orbiter data and do advanced mapping of the landing ellipse, that no matter where we landed, we would have an initial guess about where we might want to go. All of that preparation paid off.

We always felt that the placement of the landing ellipse would put us in a good position to have potential for discovery. We never really felt that we had to race out of there right away. Between the particular place that we ended up landing and having done all that preparation, we were really in a good position to have a rapid path of discovery.

However, you don't know what you've got until you see your cards, and so until that, we've been nervously waiting for the drilling to happen to see what we would get into CheMin and SAM. It worked out just about as well as we could have hoped for.

You mentioned that on reaching the site John Klein, the discoveries that were made were not serendipitous. They were not accidental or luck, but they were very deliberate in terms of actually getting to that point.

Yes, finding the right geological place was something that we did very deliberately, working with the geological model that we began to develop before we landed, that we added to after we landed with the discovery of the ancient pebble bed. All the signs were directing us towards this area.

Now, what was then serendipitous was the discovery of the clays and the sulfates. We would have been happy with either one of them, let alone both of them occurring simultaneously.

Would you have come up with different conclusions if you had found only one rather than both?

It's possible and it depends. The clays point to a neutral pH environment. The calcium sulfate could be consistent with a variety of pH's, but I think together it really adds up to a strong story for the habitable environment.

This is the first definitive habitable environment outside of Earth. Would you like to speak to that?

It feels pretty great. That's always been the goal. Before Mars, we've been getting closer and closer all the time, and we've known that the very ancient [terrain] is the place to go to. We've done a decade of mapping from orbit and we've tried places on the ground with previous rovers. All of this has been adding up to an increasingly positive situation that we've now been finally able to demonstrate.

In principle, this is an ideal kind of habitable environment for microbes, so we feel really good about that. It's the kind of thing that you look at and you realize as a team that we really have been able to do something pretty profound. We benefited from all those that came before us. We had state-of-the-art equipment and we had an incredibly capable rover with what seemed to be a highly improbable landing configuration. So we took risks where we needed to take risks and they were always what we viewed to be relatively small risks, but being aggressive in that kind of exploration has paid off and we feel really, really good about it.

I think it's kind of obvious how the orbiters have helped you with the mapping and pegging sites. How did previous rovers and the work that they've done help to lay the foundation?

Opportunity showed us the vastness over which water can be active but it also showed us that chemically and mineralogically, just water alone isn't enough. The environment at Meridani, which turned out to be a subsurface groundwater environment, was probably very acidic. It was probably extremely salty and we don't see the chemical energy that we have at John Klein. So it provided a calibration point for the orbiters that were trying to map the sulfates. Because we had an instrument on Opportunity that was able to confirm the presence of sulfate minerals, we were then able to do a cross-correlation between the surface and the orbiter. Thus the orbiter was able to do a better job of mapping.

Then with Spirit, at Gusev Crater, it took years and years and years of exploration to finally find something that was really good. When it did, it was very encouraging exploring the much more ancient part of Mars. We saw what looked like a hot spring deposit there that we weren't able to do the full chemical characterization on, lacking instruments like CheMin and SAM, but we saw that water was able to exist in a different, more promising type of environment than it had existed in Meridiani. Now here at Gale, we're exploring something that looks like an ancient river and lake type environment.

Could you kind of touch on why John Klein has good preservation potential for organics?

When you see the reducing compounds and the green color, it's an indication that, all other things being equal, you've got a better environment for preservation of organics than one in which all the minerals are red, which means they're more oxidized. If you introduce oxygen, at least in a chemical way, it can break down organics. That's why I said that really the important thing, the learning point for us going forward as a community, including the media, is that there's three parts to this preservation problem. It's not just one.

Initially, the issue is that of concentration of organic matter in the primary environment. The second thing is what's going on chemically during the conversion of sediment to rock -- what we call diagenesis -- where lithification occurs. That's where the color is relevant. If you have less oxygen available, then you have a better chance to preserve organics, but that presumes that there is something there to preserve to begin with. Then the third part is that, even if all that goes right and organics had accumulated and you also have the right colors, chemicals, and minerals, if you then expose the surface to radiation for a couple of billion years it can break those organics down.

All three of these things are important for preservation. The good thing for us is that, looking at that grayer color and finding those clay minerals and seeing iron in a not-so-oxidized state helps, but it's not the only thing.

One of the comments made during the press briefing was that, since there were four potential landing sites, there was a 75% chance that the wrong one was selected.

To be clear, the others could have also paid off. There were four final landing spots and we picked one that we thought was best for our payload. But with that we took a little bit of a risk, because within the landing site there was no evidence for sulfates or clays from orbit, which we considered to be potential leading indicators of not just water but also potentially the kinds of habitable environments that we would like to find. If we wouldn't have gone to Gale, that's not to say we wouldn't have found those things elsewhere. All four of the landing sites were known to contain clays at least in one place that would have been accessible to the rover.

Gale just seemed to offer the greatest diversity weighed against the risk that there was no signal in the landing ellipse that there were clays or sulfates there. We were willing to accept that risk. Gale Crater is full of rock, but the reason you don't see a signal from orbit is because it's got a thin coating of dust. That turns out to be a real problem for the spectrometers that look from orbit. Even a few microns-thick layer of dust is enough to prevent the signal from being seen.

So there could be other sites that have clays then that would be hidden from orbit.

Right, yep.

In preparation for solar conjunction, when the sun stands between Earth and Mars and you can't communicate with Curiosity, what kind of things will the team be doing?

We as a team will try to focus on getting more SAM and CheMin results. But mostly it will be the engineers working with Curiosity to make absolutely sure that she'll be safe during conjunction, while we have no ability to communicate.

There was a big hoopla over your NPR interview back in November. How did you feel going into that?

It was just a simple misunderstanding. My enthusiasm was about the proven capability of the payload.

Once you see an instrument as complex as SAM have everything work on it perfectly for the second time, that's when you feel really good about the mission. I
believe that, even without the results that we announced that, between the landing and the ability of the rover that was doing as well as it did and that all this sophisticated instrument payload technology was working as well as it has, that this would be historic.

It means that we as explorers can continue to do this. Even if we didn't find the stuff that we had set out to discover, you can at least turn around and say we have the capability to do this at one of the other landing sites.

Gale was a site that the team was just really happy with. It was one that we all embraced with very strong consensus as a place that harbored a lot of potential, though we didn't think that we would know about it this soon.

I think you look at something as complicated as this mission, and when you see it all working, that's what makes you feel like it succeeded.

What would you be most excited to see or discover on Mars with Curiosity?

Well, this is it. I feel at this point the rover is not going to ride off into the sunset. We're going to continue to be as aggressive and as focused and determined as we've been in the past to keep exploring.

At this point it would be an issue of what additional things we would like to see. Geologically speaking, we as a science team see that the base of Mt. Sharp has different ancient environments. We have geologic evidence that suggests there are things there that are different than they are here, and I would like for Curiosity to discover as many potentially different habitable environments as possible. So we have more to go.

Then of course, this is one that you can always hope for but you have to temper it with realistic expectation, and that is to find more complex organics.

]]> Mon, 20 MAY 2013 12:29:39 AEST Copenhagen, Denmark (SPX) Mar 22, 2013 - An international research team announces the first scientific results from one of the most inaccessible places on Earth: the bottom of the Mariana Trench located nearly 11 kilometers below sea level in the western Pacific, which makes it the deepest site on Earth.

Their analyses document that a highly active bacteria community exists in the sediment of the trench - even though the environment is under extreme pressure almost 1,100 times higher than at sea level.

In fact, the trench sediments house almost 10 times more bacteria than in the sediments of the surrounding abyssal plain at much shallower water depth of 5-6 km water.

Deep sea trenches are hot spots
Deep sea trenches act as hot spots for microbial activity because they receive an unusually high flux of organic matter, made up of dead animals, algae and other microbes, sourced from the surrounding much shallower sea-bottom. It is likely that some of this material becomes dislodged from the shallower depths during earthquakes, which are common in the area.

So, even though deep sea trenches like the Mariana Trench only amount to about two percent of the World Ocean area, they have a relatively larger impact on marine carbon balance - and thus on the global carbon cycle, says Professor Ronnie Glud from Nordic Center for Earth Evolution at the University of Southern Denmark.

Ronnie Glud and researchers from Germany (HGF-MPG Research Group on Deep-Sea Ecology and Technology of the Max Planck Institute in Bremen and Alfred Wegener Institute in Bremerhaven), Japan (Japan Agency for Marine-Earth Science and Technology), Scotland (Scottish Association for Marine Science) and Denmark (University of Copenhagen), explore the deepest parts of the oceans, and the team's first results from these extreme environments were published in the widely recognized international journal Nature Geoscience.

Diving robot
One of the team's methods was to measure the distribution of oxygen into these trench sediments as this can be related to the activity of microbes in the sediments. It is technically and logistically challenging to perform such measurements at great depths, but it is necessary in order to get accurate data on rates of bacterial activity.

"If we retrieve samples from the seabed to investigate them in the laboratory, many of the microorganisms that have adapted to life at these extreme conditions will die, due to the changes in temperature and pressure.

Therefore, we have developed instruments that can autonomously perform preprogrammed measuring routines directly on the seabed at the extreme pressure of the Marianas Trench", says Ronnie Glud. The research team has, together with different companies, designed the underwater robot which stands almost 4 m tall and weighs 600 kg. Among other things, the robot is equipped with ultrathin sensors that are gently inserted into the seabed to measure the distribution of oxygen at a high spatial resolution.

"We have also made videos from the bottom of the Mariana Trench, and they confirm that there are very few large animals at these depths. Rather, we find a world dominated by microbes that are adapted to function effectively at conditions highly inhospitable to most higher organisms", says Ronnie Glud.

The remaining "white spots"
The expedition of the Mariana Trench took place in 2010. Since then, the research team has sent their underwater robot to the bottom of the Japan Trench which is approximately 9 km deep, and later this year they are planning a dive in the world's second deepest trench, the 10.8 kilometers deep Kermadec-Tonga Trench near Fiji in the Pacific.

"The deep sea trenches are some of the last remaining "white spots" on the world map. We know very little about what is going on down there or which impact the deep sea trenches have on the global carbon cycle as well as climate regulation.

Furthermore, we are very interested in describing and understanding the unique bacterial communities that thrive in these exceptional environments.

Data from multiple deep sea trenches will allow us to find out how the general conditions are at extreme depths, but also the specific conditions for each particular trench - that may experience very different deposition regimes. This will contribute to our general understanding of Earth and its development, says Ronnie Glud.

See the article "High rate of microbial carbon turnover in sediments in the deepest oceanic trench on Earth" in Nature Geoscience.

]]> Mon, 20 MAY 2013 12:29:39 AEST Subscribe to our daily selection of space, military, environment and energy newsletters responseText http://visitor.constantcontact.com/manage/optin/ea?v=0016gbbKsaiGSpQFojVO8ZoHw%3D%3D