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RE: Martian Aliens
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Mars is often suggested as a good location to search for alien life. Despite many missions to the red planet, it's still a mystery whether life existed there in the distant past or if it is thriving there today. Attempting to answer this question was an aim of the Viking missions of 1976, but the results of those experiments were frustratingly ambiguous.

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The soil on Mars may contain microbial life, according to a new interpretation of data first collected more than 30 years ago.
The search for life on Mars appeared to hit a dead end in 1976 when Viking landers touched down on the red planet and failed to detect biological activity.
But Joop Houtkooper of the University of Giessen, Germany, said the spacecraft may in fact have found signs of a weird life form based on hydrogen peroxide on the subfreezing, arid Martian surface.
His analysis of one of the experiments carried out by the Viking spacecraft suggests that 0.1 per cent of the Martian soil could be of biological origin.

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Want to experience ancient Mars? Look no further than the Qaidam basin in north-west Tibet. A combination of cold and dryness makes it potentially the best place on Earth to find microbes similar to those on ancient Mars.
A team led by Christopher McKay of NASA Ames Research Centre in California ventured into the Qaidam wastes in search of a climate as similar to that of Mars as possible. With 1.5 centimetres of rain per year, Qaidam is not as dry as the Atacama desert in Chile, nor does its -10C average winter temperature sink to the levels found in the frigid valleys of Antarctica. Together, though, the cold and aridity provide conditions that McKay believes may emulate the Mars of 3 billion years ago, a place which may have harboured microbial life.

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Two NASA space probes that visited Mars 30 years ago may have found alien microbes on the Red Planet and inadvertently killed them, a scientist is theorizing.
The Viking space probes of 1976-77 were looking for the wrong kind of life, so they didn't recognize it, a geology professor at Washington State University said.
Dirk Schulze-Makuch presented his theory in a paper delivered at a meeting of the American Astronomical Society in Seattle, Washington.
The paper was released Sunday.

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Viking landers may have missed Martian life
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NASA’s twin Viking spacecraft may have missed signs of life during their examination of the Martian surface 30 years ago. Researchers now say that the landers’ experiments were not sensitive enough to find life and in any case may not have been able to spot the strange forms that Martian life might take.
The results from Vikings’ onboard experiments are confusing because some tests suggested the presence of organisms capable of digesting organic molecules. But heating the soil with a gas-chromatograph mass spectrometer (GCMS) to release these organic molecules found nothing, causing most scientists to rule out life. Instead they put the soil reactivity down to the presence of peroxides or other reactive substances.
Now, a paper by Rafael Navarro-Gonzalez of the University of Mexico and others demonstrates that the GCMS instrument was incapable of detecting organic compounds even in Mars-like soils from various locations on Earth. This includes Chile's Atacama desert, where other tests prove that living microbes are indeed present.
In some soils – including samples taken from Rio Tinto in Spain, which contain iron compounds similar to those detected in Mars soils by NASA's rover Opportunity, the sensitivity of the GCMS was actually a million times lower than its claimed threshold for detection.

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Electromagnetic space travel
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Life on planets such as Earth or Mars could have been seeded by electrically charged microbes from space, suggests a new study.

Since the discovery of meteorites from Mars on Earth in the 1990s, people have speculated that living microbes could have travelled back and forth between the two planets, perhaps allowing one planet to seed the other with life.
A new study suggests there may be a much gentler and steadier way for microbial life to leave a planet and travel to other worlds - and even from one solar system to another, something even the biggest impacts could not do.
The startling conclusion grew out of work by Tom Dehel, an electrical engineer at the US Federal Aviation Administration, who was investigating how electromagnetic fields in the Earth's atmosphere can affect GPS satellites and disrupt their use for aircraft navigation. He presented his findings at the biennial meeting of the international Committee on Space Research (COSPAR), in Beijing, China, this week.
Dehel calculated the effect of electric fields at various levels in the atmosphere on a bacterium that was carrying an electric charge. He showed that such bacteria could easily be ejected from the Earth's gravitational field by the same kind of electromagnetic fields that generate auroras. And these fields occur every day, unlike the extraordinarily large surface impacts needed to eject interplanetary meteorites.

The measurements of field strength vary greatly at different levels of the atmosphere - the strongest ones are near the surface, generated by thunderstorms. There are large gaps where the fields have not been measured directly, but assuming the fields extend through the whole air column, there could be an ongoing, sustained process of lofting bacteria high into the atmosphere.
Since the upward forces of the magnetic field would balance the force of gravity for tiny organisms, they could float in the upper atmosphere for years and reproduce there, giving them a chance to evolve capabilities to endure the hardships of that environment, including coping with strong UV and a near-vacuum. Such organisms would thus be well equipped to endure the rigours of a journey through space.

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NASA ROVER HELPS REVEAL POSSIBLE SECRETS OF MARTIAN LIFE

Life may have had a tough time getting started in the ancient environment that left its mark in the Martian rock layers examined by NASA's Opportunity rover. The most thorough analysis yet of the rover's discoveries reveals the challenges life may have faced in the harsh Martian environment.

"This is the most significant set of papers our team has published" - Dr. Steve Squyres of Cornell University, Ithaca, N.Y.

Dr. Steve Squyres is principal investigator for the science instruments on Opportunity and its twin rover, Spirit. The lengthy reports reflect more thorough analysis of Opportunity's findings than earlier papers.
Scientists have been able to deduce conditions in the Meridiani Planum region of Mars were sometimes wet, strongly acidic and oxidizing. Those conditions probably posed stiff challenges to the origin of Martian life.
Based on Opportunity's data, nine papers by 60 researchers in volume 240, issue 1 of the journal Earth and Planetary Science Letters discuss what this part of the Martian Meridiani Planum region was like eons ago. The papers present comparisons to some harsh habitats on Earth and examine the ramifications for possible life on Mars.

"Life that had evolved in other places or earlier times on Mars, if any did, might adapt to Meridiani conditions, but the kind of chemical reactions we think were important to giving rise to life on Earth simply could not have happened at Meridiani" - Dr. Andrew Knoll, Harvard University, Cambridge, Mass., co-author.

Scientists analysed data about stacked sedimentary rock layers 23 feet thick, exposed inside "Endurance Crater." They identified three divisions within the stack. The lowest, oldest portion had the signature of dry sand dunes; the middle portion, windblown sheets of sand with all the particles produced in part by previous evaporation of liquid water. The upper portion corresponded to layers Opportunity found earlier inside a smaller crater near its landing site.
Materials in all three divisions were wet both before and after the layers were deposited by either wind or water. Researchers described chemical evidence that the sand grains deposited in the layers had been altered by water before the layers formed. Scientists analysed how acidic water moving through the layers after they were in place caused changes such as the formation of hematite-rich spherules within the rocks.
Experimental and theoretical testing reinforces the interpretation of changes caused by acidic water interacting with the rock layers.

"We made simulated Mars rocks in our laboratory then infused acidic fluids through them. Our theoretical model shows the minerals predicted to form when those fluids evaporate bear a remarkable similarity to the minerals identified in the Meridiani outcrop" - Nicholas Tosca from the State University of New York.

The stack of layers in Endurance Crater resulted from a changeable environment perhaps 3.5 to 4 billion years ago. The area may have looked like salt flats occasionally holding water, surrounded by dunes. The White Sands region in New Mexico bears a similar physical resemblance.

"For the chemistry and mineralogy of the environment, an acidic river basin named Rio Tinto, in Spain, provides useful similarities" - Dr. David Fernandez-Remolar of Spain's Centro de Astrobiologia.

Many types of microbes live in the Rio Tinto environment, one of the reasons for concluding that ancient Meridiani could have been habitable. However, the organisms at Rio Tinto are descended from populations that live in less acidic and stressful habitats. If Meridiani had any life, it might have had to originate in a different habitat.

"You need to be very careful when you are talking about the prospect for life on Mars. We've looked at only a very small parcel of Martian real estate. The geological record Opportunity has examined comes from a relatively short period out of Mars' long history"- Dr. Andrew Knoll.

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Images with captions from the AMASE expedition to accompany the previous post:

www.carnegieinstitution.org/amase2005/

"These rocks hold potential chemical markers of fossilized life. If there is similar evidence in ancient rocks on Mars, our equipment will be able to find it" - Marilyn Fogel, biogeochemist and astrobiologist at Carnegie.

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An international team drilled ice core samples on the remote Arctic Svalbard islands at the extinct Sverrefjell volcano, has found living microbes in one-million-year-old ice.
This discovery adds support to the theory that the frozen planet Mars could also sustain life.
The researchers said that is the only place on Earth with the same minerals - called magnetite crystals - as those found on a meteorite from Mars that was discovered in the Antarctic in 1996.



The Svalbard Islands are about 500km north (80°N) of the Norwegian mainland, and are largely covered with glaciers and permafrost.

"We have discovered a microbiological oasis in natural tubes of blue ice on Svalbard. This is an extremely tough environment in which we would not have expected to find life" - Hans EF Amundsen, University of Oslo, team leader.

Space probes sent to Mars by Nasa from the United States and by the European Space Administration have showed evidence of water in the form of ice on the Red Planet.

Water is a key building block for living organisms, although many scientists believe the planet is now too cold to sustain life, a theory the Norwegian-led team's findings could challenge.

Mars is cold and dry with large caps of frozen water at its poles. However, it shares features with the Arctic Svalbard archipelago, such as permafrost, volcanoes and possibly hot springs pushing water through the frozen surface.
The team, called the Arctic Mars Analog Svalbard Expedition, began probing the islands in 2003, taking core samples at sites that include the ice-filled volcanic tubes of the Sverrefjell, which erupted through thick ice about one million years ago.

"Such ice-filled volcanic tubes are probably also found on Mars, and could be a refuge for life there"- Andrew Steele, Carnegie Institution in Washington , team scientific leader.

The team took core samples with specially designed sterile drills, to avoid contamination by surface bacteria. The living microbes were detected in the ice by special biological sensors, developed by the Jet Propulsion Laboratory.

The team then used a series of instruments to determine the number and type of microbes, partly by scanning protein micro-arrays, which are created by putting molecules in specific order on a glass plate so they can be studied by microscope.

"These protein micro-arrays, which will be used on board the space shuttle in 2006, are specially designed to show any contamination by humans. Our results show that we managed to maintain sterile conditions" - Andrew Steele.

The samples were also studied in laboratories at Carnegie, the Smithsonian Institution, the University of Oslo, Penn State University in Pennsylvania and the University of Leeds in Britain.

"Microorganisms in ice are tough survivors. Small ecosystems in the ice had apparently adapted to extremely cold conditions" - Liane Benning, University of Leeds.

The team is also developing biosensor technology that could be used to help detect any life on Mars.

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Some hardy Earth microbes could survive long enough on Mars to complicate the search for alien life, according to a new study co-authored by University of Florida researchers.
Though scientists looking for life on Mars worry about contamination from stowaway spores clinging to spacecraft, the inhospitable Martian environment is actually an effective sterilizing agent: The intense ultraviolet rays that bombard the Martian surface are quickly fatal to most Earth microbes.
However, the new study shows that at least one tough Earth species, a type of blue-green algae called Chroococcidiopsis, could live just long enough to leave a biological trace in the Martian soil - creating a potential false positive.

The study appears in the current issue of the journal Astrobiology and was co-authored by Charles Cockell of the British Antarctic Survey and UF research assistant professor Andrew Schuerger, a Mars astrobiologist and plant pathologist at UF's Institute of Food and Agricultural Sciences.
Schuerger is one of several UF researchers associated with the Kennedy Space Centre’s Space Life Sciences Laboratory, where he investigates how Earth microbes might survive, grow and adapt in simulated Martian conditions.
"It's very possible that we could send viable microorganisms to Mars and then bring some of those same Earth bugs back with us." - Andrew Schuerger.

The researchers examined a dry-tolerant and radiation-resistant algae that thrives in Earth's most extreme conditions, from the hot, arid Negev desert in Israel to the frigid Antarctic Ross Desert. This bacterium has not been found on the surfaces of spacecraft, but it represents a worst-case scenario for scientists.
"The only way to find out (if there's life on Mars) is by going there and studying it, yet we take with us the potential to contaminate our own studies. It's the biological Heisenberg principle. Can we do the studies without contaminating what we're looking at? So we have to have some idea of whether or not Earth life is likely to survive (on other planets)." - John Rummel, NASA's current Planetary Protection Officer.
NASA created the Planetary Protection Office to safeguard against transferring potentially harmful organisms to or from Earth during space exploration.

To test the limits of the algae's endurance, the researchers subjected it to a simulated Martian atmosphere, re-created within a 5-foot-long stainless steel barrel-shaped chamber.
On Mars, average global temperature is -78 degrees Fahrenheit, atmospheric pressure is one-hundredth of the Earth's and UV rays striking the surface is three times as intense as on the ozone-protected Earth - enough to produce a severe sunburn on exposed skin in minutes. Of these harsh conditions, the UV rays are the most powerful sterilizing agent.

The researchers found that when exposed to the full spectrum of these rays, 99.9 percent of the algae in the chamber died within five minutes - significant when compared with the survival time of other microbes exposed to the same conditions: 15 seconds.
However, the algae also left chemical traces of their existence that were detectable for several more hours. Those "biosignatures" included component molecules such as chlorophyll and the measured activity of enzymes involved in cell membrane formation. Enzyme activity persisted for an hour, while traces of chlorophyll remained for up to four hours.

"This demonstrates that looking for biogenic signatures alone will complicate the process of looking for life. You have to do both, you have to do a number of different procedures, and they have to complement one another." - John Rummel.
The algae also managed to survive when it was shielded from the direct onslaught of UV rays by a millimetre-thick layer of sand or rock. Such a scenario could occur if a robot lands on the Martian surface and its pads sink immediately into the sand. However, though buried microbes may survive for some period of time, they are still subject to Mars' low atmospheric pressure, high aridity and temperature extremes.

Under those conditions, they wouldn't necessarily grow or reproduce and are therefore unlikely to pose an ongoing contamination threat, he added.
"You might have a very lonely cyanobacterium waiting for something to happen." - John Rummel.

The paper's other authors include Daniela Billi of the University of Rome; E. Imre Friedmann of NASA's Ames Research Centre; and Dr. Corinna Panitz of the German Aerospace Centre in Koln. Space Life Sciences Centre.



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