Subdued seasonality might be linked to the emergence of complex life on Earth around 600 million years ago. On alien worlds, extreme seasonal spikes and plunges in temperature could likewise determine whether life teems, scrapes by, or dies.

Seasons arise when the axis of a planet's spin is tilted relative to the plane of the planet's orbit. Recent research has suggested that a loss of axial tilt and its attendant seasonality, which helps moderate global temperatures, could doom extraterrestrial creatures. Scientists are also considering the opposite case: worlds where blazing summers and devastatingly frigid winters make the development of life with any complexity a long shot.

"Axial tilt, or obliquity, is a crucial parameter for climate and the possible habitability of a planet," said Rene Heller, a postdoctoral research associate at the Leibniz Institute for Astrophysics in Potsdam, Germany. Heller was the lead author on two papers last year on obliquity loss due to tidal interactions on habitable planets around red dwarf stars.

Seasonally maladjusted
Many phenomena influence obliquity over a planet's history. Major examples include the impacts of large cosmic bodies, as well as the gravitational pulls from companion planets and central stars. Over the course of a year on a tilted planet, varying amounts of warming sunlight strike the northern and southern hemispheres.

The Earth presently has an obliquity of about 23.5 degrees. Along with daily rotations, this moderate obliquity ensures that the temperature differences between the coldest polar and hottest desert regions are not too extreme.

Unlike our planet, another world with a low axial tilt of no more than a few degrees would not experience much seasonality. The colder poles would lead to a narrower habitable region, and if coupled with a too-hot equator could render the world a difficult place for complex life. It is an even grimmer picture for high-obliquity planets in a planetary system's "Goldilocks" zone, the orbital band where water can stay in liquid form on a world's surface.

Take the case of an Earth-like planet with an obliquity close to that of Uranus, about 90 degrees. The north pole would point at the central star for a quarter of the year and then directly away for another quarter.

"Your northern pole will be boiled during part of the year while the equator gets little sunlight," said Heller. Meanwhile, "the southern pole freezes in total darkness." Essentially, the conventional notion of a scorching hell dominates one side of the planet, while an ultra-cold hell like that of Dante's Ninth Circle prevails on the other.

Then, to make matters worse, the hells reverse half a year later. "The hemispheres are cyclically sterilized, either by too strong irradiation or by freezing," Heller said.

Some like it hot . . . or cold
Life - always resilient - could still find ways to persist on planets that spin on their "sides," Uranus-style. Maybe migrating critters could follow a survivable, fast-shifting climatic zone while others find refuge at the equator. Hardy organisms might just ride out the temperature extremes. Examples of these rugged creatures right here on Earth, mostly bacteria, are known naturally enough as "extremophiles."

A class of these organisms, called thermophiles, thrives in hot springs and in the lightless oceanic depths around hydrothermal vents. The species Methanopyrus kandleri can reproduce in high-pressure waters hotter than 250 degrees Fahrenheit. On the other end, psychrophiles grow in ice-covered cavities of briny seawater down to 5 degrees Fahrenheit.

When conditions get too hot or cold, sporulating bacteria go into stasis, encasing themselves in tough structures called endospores. The microorganisms can lie dormant in ice for millions of years and upon thawing go right back to replicating.

Earth becomes more Earth-like
For more than the simplest biota, such feats of durability would surely pose a lot of challenges on exoplanets with higher obliquity than Earth's, though far less than that of Uranus.

"Perhaps an obliquity of just 40 degrees would be tough for complex animals due to the very hot summers and cold winters that would affect much of the globe," noted George Williams, a geologist at the University of Adelaide in Australia.

Climatic conditions of this very sort might have held back the evolution of big and diverse creatures on our planet, Williams suggests. Prior to about 580 million years ago, scientists think most of earthly life consisted of microscopic algae and bacteria. Complex animals such as jellyfish and worms arrived on the scene thereafter.

Then, starting about 540 million years ago, in what is known as the Cambrian explosion, life went nuts. All sorts of intricate body types sporting spines, shells, eyes, legs and more suddenly show up in the fossil record.

Could Earth have once possessed a high obliquity? Computer models say yes. The cataclysmic impact with a Mars-sized body 4.5 billion years ago, thought to have created the Moon, could have knocked Earth's spin axis well off-kilter from the plane of the planet's orbit. Intriguingly, some geological evidence is consistent with Earth having a high obliquity for much of its history, up until about 600 million years ago.

Glaciers provide crucial information in this regard. As shown by numerous geophysicists headed by Phil Schmidt at the Commonwealth Scientific and Industrial Research Organisation in Australia, glaciers used to form preferentially in formerly low latitudes. (Somewhat counterintuitively, an obliquity exceeding 54 degrees renders the equator cooler than the poles, on average.)

Magnetic directions fixed in glacial deposits have revealed this ancient icy activity. Associated sand-wedge structures, like those that occur in modern-day polar regions, suggest big seasonal temperature fluctuations as well. From winter to summer near the former equator, temperatures varied in excess of 100 degrees Fahrenheit. If that were to occur today, blizzards could dump snow on the Amazon rainforest.

Geological markers of high obliquity peter out around the so-called Precambrian-Phanerozoic boundary. After this time, significant glaciations occurred in just the high latitudes, and life took off.

"There seems to have been a dramatic improvement in the habitability of the Earth at around the Precambrian-Phanerozoic boundary," Williams said. "I have suggested that reduction of obliquity was the main cause of this major change in habitability." Models of the Earth's climate with a high obliquity by atmospheric physicist Gregory Jenkins at Howard University buttress this idea.

Of course, many other explanations have been offered for the Cambrian explosion, though each has its drawbacks. Ideas include a greater concentration of atmospheric oxygen or calcium or phosphorus in seawater, or even the evolution of eyes jumpstarting biodiversity.

Williams' hypothesis has its own big gap: a mechanism that could have clipped the planet's tilt by about 30 degrees in 100 million years prior to the Earth's oldest confirmed circumpolar glaciation. Research into the history of tectonic processes within the Earth and gravitational interaction with the Moon may illuminate the matter.

A "Goldilocks" obliquity?
At this point in exoplanetary research, very little is known about the characteristics of most alien worlds beyond their size, mass and orbital period. Discerning axial tilts and the effect they have on planetary habitability will be an important aspect of the search for alien life in the decades ahead.

It could turn out that Earth's obliquity of 23.5 degrees, like its orbital distance from the Sun, is a "Goldilocks" figure for seasonality - not too extreme in either direction - and therefore ideal for complex life.

"Obliquities of bodies in the Solar System have been studied extensively," said Heller. "But with exoplanets we are entering new territory."

]]> Thu, 09 FEB 2012 08:59:10 AEST Laguna Negra, Chile (SPX) Jan 31, 2012 - PLL has been moved to its summer home on the northwest finger of Laguna Negra. Meanwhile, back on the south shore, Jeff Moersch, an assistant professor of Earth and planetary sciences at the University of Tennessee, and his graduate student, Robert Jacobsen, arrived at PLL Base Camp and began work characterizing the geology of the Laguna Negra basin.

Jeff and Robert are conducting two sets of experiments. One is ground-truthing, or verifying, mineralogical data collected by orbiting satellites.

The Andes are among the most geologically active regions on Earth. The landscape is continually pushed upward and twisted by the pressure of tectonic plates, and volcanoes explode frequently, sometimes with catastrophic results. These processes, as well as rain and snow wearing away rock and turning it to sediment, have heavily reworked the terrain.

A number of orbiting satellites have crisscrossed the Earth, recording infrared spectra that can reveal what types of rocks are present in which locations. Different types of minerals absorb infrared light at different combinations of frequencies, and it is these absorption patterns that orbiting satellites record.

Satellites in orbit, however, have to do their observing through the Earth's atmosphere, which can distort their results. Jeff and Robert brought with them a portable infrared spectrometer, an instrument that does the same thing as the spectrometers onboard a satellite, but that can be carried in a backpack.

By walking up to various types of rocks and recording infrared spectra up-close, without the interference of the atmosphere, they can obtain what is known as "ground-truth" data.

Taking these ground measurements in a few locations will enable them to calculate the distortions caused by the atmosphere and to subtract the atmospheric effect from spectral maps of the entire region to get a more accurate picture of precisely what types of mineral combinations are present.

That, in turn, will provide background information for other PLL team members interested in understanding precisely what types of minerals are being washed down from the mountains that surround Laguna Negra into the lake, and by extension, what types of nutrients are - and are not - available to the organisms that live in the lake.

Their second experiment involves a thermal camera. This, too, sees in the infrared, but rather than looking at spectral data at small points on individual rocks, the thermal camera takes a picture of the heat being radiated by large areas of the landscape. Jeff and Robert set the camera up at PLL Base Camp, pointed toward a distant shore of the lake and portions of the surrounding mountains, and plan to record a series of images over a period of a few days.

What they're interested in is not so much any one individual image, but rather how the "heat map" recorded by their imager changes during the course of the day.

The entire landscape heats up during the day, under intense sun that sends us all running for sunscreen (and bemoaning the lack of shade). But different materials retain or lose their heat in very different ways during the cold nights. Large boulders, for example, retain more heat than small grains of sand. Similarly, wet ground retains more heat than drier terrain.

The thermal imager thus can create maps that show how materials of different sizes have been sorted, or separated out, by glacial action and by the movement of water on the surface. That information, in turn, can provide an understanding of how water and ice have moved through the landscape in the past, and how it is behaving today.

The geologic information from these two experiments will provide a foundation for understanding how the Laguna Negra basin's ecosystem is evolving in the present period of rapid deglaciation. It may also help planetary scientists interpret images of the geologic remains of past periods of deglaciation on Mars.

]]> Thu, 09 FEB 2012 08:59:10 AEST Hat Creek, Calif. (UPI) Jan 31, 2012 - The search for intelligent life elsewhere in the universe is back on, after a yearlong delay due to funding problems, U.S. researchers said.

Forty-two radio telescopes, known as the Allen Telescope Army, have set up shop near Lassen Peak, Calif., searching for radio signals from the constellation Cygnus. The project was operated by the University of California until last year, when it ran out of money, The New York Times reported Monday.

The current search for any alien transmission is conducted with scrounged equipment, part-time astronomers' talents and donations from Silicon Valley executives, the newspaper said.

While the U.S. Air Force is negotiating a contract with the group to help it locate errant satellites, the astronomers have returned to the site, named after Microsoft founder and philanthropist Paul Allen, whose $25 million contribution began the project.

No government money has been spent since 1993 on monitoring the skies for signs of extraterrestrial life, the report said.

]]> Thu, 09 FEB 2012 08:59:10 AEST Laguna Negra, Chile (SPX) Jan 27, 2012 - The Planetary Lake Lander has been moored for the past week a short distance off the southern shore of Laguna Negra, near PLL Base Camp. Its proximity to camp enabled engineers to test its data-sampling and communications equipment. And to easily get out to the device to fix whatever annoying problems - miswired connections, transmission glitches - cropped up.

Now that the exciting world of the northwest shore has been explored and found to be a scientific wonderland, however, the time has come to relocate. A decision was made a couple of days ago to move PLL to a spot just off the northwest shore, where the waters of Victoria's Cascade tumble into the lake, bringing with them nutrient-rich glacial sediments. This location will provide very different information than the crystal-clear, and nutrient-poor, waters near Base Camp.

The spot chosen offered a finely tuned mix of characteristics. There was the glacial melt water, of course, fantastic for science. But there was also, conveniently, a pair of underwater landslides, discovered during Chris Haberle's bathymetric survey of the area. That was good for anchoring PLL so it stays put for the next three months.

And to top it off, the arc of the sun across the sky lined up nicely with PLL's solar panels, so there will be no worry the scientific equipment will run short on power.

Yesterday, Trey and Liam, along with Chris and Cristian, spent the day preparing PLL for its journey to and installation in its new home. That meant, first, moving it from its temporary home to Launch Point, on the lake's southwest shore. The advantage of working at Launch Point is that it's the one spot along the lakeshore accessible by road.

The scientific and communications equipment had already been checked and double-checked. What remained to be done was outfitting PLL with new anchors. Two 140-pound anchors.

These were too heavy to lift, so they had to be disassembled, carried onto the PLL's pontoon in pieces, and then reassembled. While moored off the southern shore of the lake, PLL has been held in place by relatively lightweight anchors, but for it's longer-term stay on the northwest shore, it needs to be anchored more securely.

Assembling the anchors was only step one. Liam spent most of the day yesterday "flaking" the ropes attached to the anchors. This is not a problem the average person has to be concerned with, but when you're floating on the surface of deep, hypothermia-inducing water, on a moderately unstable platform, and planning to drop overboard a pair of 140-pound anchors attached to very long ropes, it's a good idea to prepare carefully.

You might think the best approach would be to coil the rope in a cute little circular pile. Turns out, that's not the case. As you may have experienced with a garden hose, what appears to be neatly coiled, when pulled on, can suddenly become hopelessly tangled.

That's not such a big problem when you're dealing with a garden hose. But when you're dealing with a long rope, with a 140-pound weight attached to one end, and when you are about to send that weight hurtling down through 45 meters of water, you want the rope to play out smoothly, not to snag on anything. Such as a piece of expensive equipment. Or someone's ankle. Because whatever it snags on will (a) probably get broken; and (b) be dragged down into the deep with little hope of recovery.

So you flake the rope. Which means you stack it up in what looks like a random back-and-forth pile, but a pile that, crucially, is snag-resistant. And then you flake the other rope. And then you go back and flake the first rope again, just to be sure. And then the second rope, again. And a third time, to be really, really sure.

All this flaking was time well spent. Today, the PLL was sailed to its new location, the ropes were deployed without incident, and PLL was secured for its three-month stay in the northwest waters of Laguna Negra.

It was after that that the problem occurred.

When PLL engineers pulled out their ruggedized, work-anywhere laptop to "talk" to the equipment onboard the lander, they couldn't establish communication. That was confusing. And annoying. Here they were standing right next to the device they were trying to communicate with, a device they had communicated with successfully from the Robo Dome only the day before, and suddenly a communications link that had been working perfectly had gone awry.

Long story short: when the laptop had been in the Robo Dome, it had been attached to an external monitor. And the window for the software package that talked to PLL had been displayed on that external monitor. But out on the water, there was only the laptop. No external monitor.

You'd think the software could figure that out and display the window in question on the laptop screen. But if you thought that, you'd be wrong. Instead, all it could do was issue a cryptic error message. Fortunately, once the team got back to the Robo Dome and reattached the external monitor, communication was re-established.

Now that everything's working as it should, PLL is set to spend the next three months collecting data and transmitting it back to the IRG group at NASA Ames Research Center in Moffett Field, California. At that point, some members of the PLL team will retrieve the device and ship it back to Ames, where it will get upgraded with both new hardware and new software, before being brought back to Laguna Negra next summer.

The data that it sends back will form the basis for the development of the first version of PLL's autonomous control software. Developing that autonomous software is the primary technology goal of the PLL ASTEP (Astrobiology Science and Technology for Exploring Planets) project. It's not yet clear how "smart" the software will be in Year 2 of the project.

Ultimately, the goal is to program PLL to make decisions on its own about what events are of scientific interest and about how best to study those events. But in Year 2, it may not implement autonomous decisions, but rather limit itself to performing the analysis that would lead to such decisions.

]]> Thu, 09 FEB 2012 08:59:10 AEST Galveston TX (SPX) Jan 27, 2012 - Discoveries made in some underwater caves by Texas A and M University at Galveston researchers in the Bahamas could provide clues about how ocean life formed on Earth millions of years ago, and perhaps give hints of what types of marine life could be found on distant planets and moons.

Tom Iliffe, professor of marine biology at the Texas A and M-Galveston campus, and graduate student Brett Gonzalez of Trabuco Canyon, Calif., examined three "blue holes" in the Bahamas and found that layers of bacterial microbes exists in all three, but each cave had specialized forms of such life and at different depths, suggesting that microbial life in such caves is continually adapting to changes in available light, water chemistry and food sources.

Their work, also done in conjunction with researchers from Penn State University, has been published in Hydrobiologia.

"Blue holes" are so named because from an aerial view, they appear circular in shape with different shades of blue in and around their entrances. There are estimated to be more than 1,000 such caves in the Bahamas, the largest concentration of blue holes in the world.

'We examined two caves on Abaco Island and one on Andros Island," Iliffe explains.

"One on Abaco, at a depth of about 100 feet, had sheets of bacteria that were attached to the walls of the caves, almost one inch thick. Another cave on the same island had bacteria living within poisonous clouds of hydrogen sulfide at the boundary between fresh and salt water.

These caves had different forms of bacteria, with the types and density changing as the light source from above grew dimmer and dimmer.

"In the cave on Andros, we expected to find something similar, but the hydrogen sulfide layer there contained different types of bacteria," he adds.

"It shows that the caves tend to have life forms that adapt to that particular habitat, and we found that some types of the bacteria could live in environments where no other forms of life could survive. This research shows how these bacteria have evolved over millions of years and have found a way to live under these extreme conditions."

Iliffe says the microbes change where the salt water meets fresh water within the caves and use chemical energy to produce their food. They can survive in environments with very low amounts of oxygen and light.

There are tens of thousands of underwater caves scattered around the world, but less than 5 percent of these have ever been explored and scientifically investigated, Iliffe notes.

"These bacterial forms of life may be similar to microbes that existed on early Earth and thus provide a glimpse of how life evolved on this planet," he adds.

"These caves are natural laboratories where we can study life existing under conditions analogous to what was present many millions of years ago.

"We know more about the far side of the moon than we do about these caves right here on Earth," he adds.

"There is no telling what remains to be discovered in the many thousands of caves that no one has ever entered. If life exists elsewhere in our solar system, it most likely would be found in water-filled subterranean environments, perhaps equivalent to those we are studying in the Bahamas."

Over the past 30 years, Iliffe has discovered several hundred species of marine life, and has probably explored more underwater caves - at least 1,500 - than anyone in the world, examining such caves in Australia, the Caribbean, Mediterranean and North Atlantic regions of the world.

]]> Thu, 09 FEB 2012 08:59:10 AEST Los Angeles CA (SPX) Jan 26, 2012 - Scientists at USC have uncovered evidence that even when hydrothermal sea vents go dormant and their blistering warmth turns to frigid cold, life goes on. Or rather, it is replaced.

A team led by USC microbiologist Katrina Edwards found that the microbes that thrive on hot fluid methane and sulfur spewed by active hydrothermal vents are supplanted, once the vents go cold, by microbes that feed on the solid iron and sulfur that make up the vents themselves.

These findings - based on samples collected for Edwards by US Navy deep sea submersible Alvin (famed for its exploration of the Titanic in 1986) - provide a rare example of ecological succession in microbes.

The findings were published in mBio in an article authored by Edwards, USC graduate researcher Jason Sylvan, and Brandy Toner of the University of Minnesota.

Ecological succession is the biological phenomenon whereby one form of life takes the place of another as conditions in an area change - a phenomenon well-documented in plants and animals.

For example, after a forest fire, different species of trees replace the older ones that had stood for decades.

Scientists have long known that active vents provided the heat and nutrients necessary to maintain microbes. But dormant vents - lacking a flow of hot, nutrient-rich water - were thought to be devoid of life.

Hydrothermal vents are formed on the ocean floor with the motion of tectonic plates. Where the sea floor becomes thin, the hot magma below the surface creates a fissure that spews geothermally heated water - reaching temperatures of more than 400 degrees C.

After a (geologically) brief time of actively venting into the ocean, the same sea floor spreading that brought them into being shuffles them away from the hotspot. The vents grow cold and dormant.

"Hydrothermal vents are really ephemeral in nature," said Edwards, professor of biological sciences at the USC Dornsife College of Letters, Arts and Sciences.

Microbial communities on sea floor vents have been studied since the vents themselves were first discovered in the late 1970s. Until recently, little attention had been paid to them once they stopped venting, though.

Sylvan said he would like to take samples on vents of various ages to catalogue exactly how the succession from one population of microbes to the next occurs.

Edwards, who recently returned from a two-month expedition to collect samples of microbes deep below the ocean floor, said that the next step will be to see if the ecological succession is mirrored in microbes that exist beneath the surface of the rock.

"The next thing is to go subterranean," she said.

]]> Thu, 09 FEB 2012 08:59:10 AEST Moscow (RIA Novosti) Jan 26, 2012 - NASA has dismissed the sensational claim by a Russian scientist that there is life on Venus, saying that the "disc" seen moving on the surface was in fact a lens cap.

Earlier this month an article published in Solar System Research magazine reported several objects resembling living beings detected on photos made by the Soviet probe that landed on Venus in 1982.

Leonid Ksanfomaliti of the Space Research Institute of Russia's Academy of Sciences published research that analyzed photos made by the Venera-13 lander showing several objects resembling "a disk," "a black flap" and "a scorpion." All of them "emerge, fluctuate and disappear," the scientist said, referring to their changing location on different photos and traces on the ground.

But NASA photo analysts dismissed his claims. "It makes much more sense that it's a piece of the lander designed to break off during the deployment of one of the scientific instrument," The Daily Mail reported on Tuesday, quoting Jonathon Hill, a NASA mission planner.

Experts also said that the "scorpion" found by Ksanfomaliti is also just noise in a digital image.

No evidence of life on Venus, where the surface temperature is 464 degrees Celsius (867 degrees Fahrenheit), has ever been found.

Source: RIA Novosti

]]> Thu, 09 FEB 2012 08:59:10 AEST York UK (SPX) Jan 26, 2012 - Organic chemists at the University of York have made a significant advance towards establishing the origin of the carbohydrates (sugars) that form the building blocks of life.

A team led by Dr Paul Clarke in the Department of Chemistry at York have re-created a process which could have occurred in the prebiotic world.

Working with colleagues at the University of Nottingham, they have made the first step towards showing how simple sugars -threose and erythrose-developed. The research is published in Organic and Biomolecular Chemistry.

All biological molecules have an ability to exist as left-handed forms or right-handed forms. All sugars in biology are made up of the right-handed form of molecules and yet all the amino acids that make up the peptides and proteins are made up of the left-handed form.

The researchers found using simple left-handed amino acids to catalyse the formation of sugars resulted in the production of predominately right-handed form of sugars. It could explain how carbohydrates originated and why the right-handed form dominates in nature.

Dr Clarke said: "There are a lot of fundamental questions about the origins of life and many people think they are questions about biology. But for life to have evolved, you have to have a moment when non-living things become living - everything up to that point is chemistry.

"We are trying to understand the chemical origins of life. One of the interesting questions is where carbohydrates come from because they are the building blocks of DNA and RNA. What we have achieved is the first step on that pathway to show how simple sugars -threose and erythrose-originated. We generated these sugars from a very simple set of materials that most scientists believe were around at the time that life began."

]]> Thu, 09 FEB 2012 08:59:10 AEST Moffett Field CA (SPX) Jan 24, 2012 - The bottom of a glacier is not the most hospitable place on Earth, but at least two types of bacteria happily live there, according to researchers.

The bacteria - Chryseobacterium and Paenisporosarcina - showed signs of respiration in ice made in the laboratory that was designed to simulate as closely as possible the temperatures and nutrient content found at the bottom of Arctic and Antarctic glaciers, said Corien Bakermans, assistant professor of microbiology, Penn State Altoona.

Bakermans said that carbon dioxide levels in the laboratory-made ice containing the bacteria, which were collected from glaciers in Greenland and Antarctica, indicated that respiration was occurring at temperatures ranging from negative 27 to positive 24 degrees Fahrenheit.

Bakermans, who worked with Mark Skidmore, associate professor of geology, Montana State University, determined the level of respiration by measuring the amount of carbon dioxide in the laboratory-made ice.

While humans obtain energy from sugar, the bacteria in this experiment used acetate, a form of vinegar. Like human respiration, the microbes take in the molecules, extract energy from them and breathe out carbon dioxide as a waste product.

Bakermans said the study may have implications for the search for life on other planets, like Mars, because some places on Mars are in the same temperature range as the temperature levels recorded during the experiment.

"Although there are a lot of other factors involved for life to take hold on other planets," Bakermans said, "we can still say that if microbes on Earth can do this, then there's the potential, at least, that microbes can do this on Mars."

Glaciers and ice sheets represent large ecosystems that cover more than 10 percent of the Earth and contain approximately 78 percent of the world's fresh water.

The researchers, who reported their findings in a recent issue of Environmental Microbiology Reports, said that respiration was reported at all temperatures examined.

The respiration rate of the microbes increased as the temperature rose. While the respiration rates of the bacteria are slow compared to the human respiration, the microbes could maintain cell structure and viability throughout the observed temperature range.

The researchers also performed a staining test to measure reproduction and cell viability. When cells are alive or dead, they leave a chemical footprint of those states. By applying stains to the bacteria in the laboratory-made ice, the researchers can find those chemicals and determine if the cells are alive and healthy.

Bacteria seem to grow best in cracks and crevices within the ice, Bakermans said. The cracks in the ice create channels that allow water and nutrients to circulate.

"It's hard for nutrients to be exchanged in the ice," Bakermans said. "But these channels appear to give the microbes access to nutrients."

The bottom of glaciers may be more hospitable for the microbes than other parts of the glacier because the areas draw warmth and nutrients from the earth, Bakermans said.

]]> Thu, 09 FEB 2012 08:59:10 AEST University Park PA (SPX) Jan 20, 2012 - The bottom of a glacier is not the most hospitable place on Earth, but at least two types of bacteria happily live there, according to researchers.

The bacteria - Chryseobacterium and Paenisporosarcina - showed signs of respiration in ice made in the laboratory that was designed to simulate as closely as possible the temperatures and nutrient content found at the bottom of Arctic and Antarctic glaciers, said Corien Bakermans, assistant professor of microbiology, Penn State Altoona.

She said that carbon dioxide levels in the laboratory-made ice containing the bacteria, which were collected from glaciers in Greenland and Antarctica, indicated that respiration was occurring at temperatures ranging from negative 27 to positive 24 degrees Fahrenheit.

Bakermans, who worked with Mark Skidmore, associate professor of geology, Montana State University, determined the level of respiration by measuring the amount of carbon dioxide in the laboratory-made ice.

While humans obtain energy from sugar, the bacteria in this experiment used acetate, a form of vinegar. Like human respiration, the microbes take in the molecules, extract energy from them and breathe out carbon dioxide as a waste product.

Bakermans said the study may have implications for the search for life on other planets, like Mars, because some places on Mars are in the same temperature range as the temperature levels recorded during the experiment.

"Although there are a lot of other factors involved for life to take hold on other planets," Bakermans said, "we can still say that if microbes on Earth can do this, then there's the potential, at least, that microbes can do this on Mars."

Glaciers and ice sheets represent large ecosystems that cover more than 10 percent of the Earth and contain approximately 78 percent of the world's fresh water.

The researchers, who reported their findings in a recent issue of Environmental Microbiology Reports, said that respiration was reported at all temperatures examined.

The respiration rate of the microbes increased as the temperature rose. While the respiration rates of the bacteria are slow compared to the human respiration, the microbes could maintain cell structure and viability throughout the observed temperature range.

The researchers also performed a staining test to measure reproduction and cell viability. When cells are alive or dead, they leave a chemical footprint of those states. By applying stains to the bacteria in the laboratory-made ice, the researchers can find those chemicals and determine if the cells are alive and healthy.

Bacteria seem to grow best in cracks and crevices within the ice, Bakermans said. The cracks in the ice create channels that allow water and nutrients to circulate.

"It's hard for nutrients to be exchanged in the ice," Bakermans said. "But these channels appear to give the microbes access to nutrients."

The bottom of glaciers may be more hospitable for the microbes than other parts of the glacier because the areas draw warmth and nutrients from the earth, Bakermans said.

]]> Thu, 09 FEB 2012 08:59:10 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