Icy asteroids may have seeded life on Earth, claim scientists

April 29, 2010 By Leave a Comment

London, April 29 (ANI): NASA has revealed compelling evidence of life on Mars.

NASA’s Spirit and Opportunity missions have disclosed signs of sulphates on Mars, which evidently means there could be water on the Red Plant and consequently life.

While previous missions have also suggested the presence of water on Mars, NASA says the recent evidence is more concrete.

Boffins are especially excited over the discovery of gypsum – a sulphate found in fossils in the Mediterranean.

Jack Farmer, researcher at the Arizona State University, in Tempe, Arizona, was “optimistic” there was – or had been – life on Mars.

“One, thanks to Opportunity and the rovers and orbital imaging it is clear that there are literally vast areas of Mars that are carpeted with various sorts of sulphates, including gypsum,” the Sun quoted Bill Schopf, researcher at the University of California in Los Angeles, as saying.

Schopf went on: “Two, it turns out on earth there just hasn””t been hardly any work done at all to show whether gypsum ever includes within it preserved evidence of former life.

“The age doesn””t matter. We just didn””t know that fossils and organic matter and things like that were well preserved within gypsum.

“So, three, it turns out that now we have made that first step we are going to find out how widespread it is in other sulphate deposits on earth.

“And those lines of evidence will then give us a way to justify going to Mars and looking at gypsum because it looks as though based on these findings that is going to turn out to be a really excellent place to find evidence of ancient life, regardless of age, if in fact it is there.”

According to Dr Steve Squyres, of Cornell University, Ithaca, New York, a sample of Mars rock would help establish the presence of life on the planet.

He believes the presence of Methane in the Martian atmosphere hinted at the possibility of life.

Squyres said: “Methane is a molecule that should go away very quickly. We need to send a mission to find out if the source is biological.

“We also need to send a mission to return samples from Mars. That would enable scientists to find out whether Mars might ever have harboured life.

He added: “If we are ever going to show if there was ever life on Mars, I think we””re going to have to study samples back on Earth.” (ANI)

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Traces of laughing gas could aid search for life on Mars

April 28, 2010 By Leave a Comment

London, April 28 (ANI): Traces of nitrous oxide in the atmosphere of Mars can contribute to the search for life on the Red Planet, according to a new study.

The research in Antarctica revealed a non-organic mechanism for the production of nitrous oxide (laughing gas), an important greenhouse gas.

A team of scientists, led by biogeochemists from the University of Georgia, made the discovery at Don Juan Pond in the Dry Valleys of Antarctica.

The pond is almost 18 times saltier than the Earth”s oceans and virtually never freezes, even in temperatures of more than 40 degrees below zero Fahrenheit.

The discovery could help space scientists understand the meaning of similar brine pools in Mars since its ecosystem most closely resembles that of Don Juan Pond.

The study adds an intriguing new variable to growing evidence that there has been – and may still be – liquid water on Mars, a usual prerequisite for the formation of life.

In fact, the new findings could help space scientists develop sensors for detecting such brines on Mars – thus narrowing the search for places where life may exist.

Lead author Samantha Joye, a faculty member in the department of marine sciences in the Franklin College of Arts and Sciences, said: “The pond”s soils and brines and the surrounding rock types are similar to those found on Mars.

“So it provides an ideal location to assess microbial activity in extreme environments. While we did not detect any ”bio-gases” such as hydrogen sulfide and methane, we did, surprisingly, measure high concentrations of nitrous oxide, which is normally an indicator of microbial activity. We needed to find out whether a non-organic process could account for this nitrous oxide production.”

Joye went on: “What we found was a suite of brine-rock reactions that generates a variety of products, including nitrous oxide and hydrogen.

“In addition to Don Juan Pond, this novel mechanism may occur in other environments on Earth as well and could serve as both an important component of the Martian nitrogen cycle and a source of fuel [hydrogen] to support microbial chemosynthesis.”

Even more interesting, perhaps, is that the results suggest that an additional mechanism – the reaction of brine-derived nitrates with basaltic rock – could be a “previously unrecognized means for mobilizing nitrate from the surface soils . . . and returning it to the Martian atmosphere as nitrous oxide,” Joye stated.

The discovery of the new mechanism opens numerous questions that must be studied, including the possibility that the process is taking place in other extreme Antarctic habitats or that it might contribute to nitrous oxide in temperate soils – a possible new clue to understanding greenhouse gases involved in global warming.

The most crucial result, however, may be in understanding how similar brine pools on Mars might work and whether they could support life.

The study has appeared in the journal Nature Geoscience. (ANI)

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Earth bacteria may contaminate Martian environs

April 28, 2010 By Leave a Comment

Washington, April 28 (ANI): Scientists are expressing fears that some bacteria common to spacecrafts may even survive on Mars and contaminate the Red Planet”s environment.

The search for life on Mars remains a stated goal of NASA”s Mars Exploration Program and Astrobiology Institutes.

To preserve the pristine environments, the bioloads on spacecraft headed to Mars are subject to sterilization designed to prevent the contamination of the Martian surface.

Despite sterilization efforts made to reduce the bioload on spacecraft, recent studies have shown that diverse microbial communities remain at the time of launch.

The sterile nature of spacecraft assembly facilities ensures that only the most resilient species survive, including acinetobacter, bacillus, escherichia, staphylococcus and streptococcus.

Researchers from the University of Central Florida replicated Mars-like conditions by inducing desiccation, hypobaria, low temperatures, and UV irradiation.

During the week-long study they found that Escherichia coli a potential spacecraft contaminant, may likely survive but not grow on the surface of Mars if it were shielded from UV irradiation by thin layers of dust or UV-protected niches in spacecraft.

The scientists said: “If long-term microbial survival is possible on Mars, then past and future explorations of Mars may provide the microbial inoculum for seeding Mars with terrestrial life.

“Thus, a diversity of microbial species should be studied to characterize their potential for long term survival on Mars.”

The study has appeared in the April 2010 issue of the journal Applied and Environmental Microbiology. (ANI)

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Sulphur could contain signatures of life on Mars

March 16, 2010 By Leave a Comment

London, March 16 (ANI): New evidence indicates that signs of life on Mars might be all over the Red Planet in the form of sulphur, and the next Mars lander should be able to detect the proof.

No mission to Mars has ever found complex carbon-based molecules, from which life as we know it is built.

But sulphur is everywhere on Mars. In fact, it is more abundant there than on Earth, and it could contain one of the signatures of life.

On Earth, the activity of some microbes converts one class of sulphur-containing compounds, the sulphates, into another, the sulphides.

The microbes prefer to work with the lighter sulphur-32 isotope, so the sulphides they produce are relatively deficient in the heavier isotope, sulphur-34.

Planetary scientists have long wondered whether we could use this pattern to discern signs of life on Mars.

Now, the prospects for this technique look better than ever.

According to a report in New Scientist, John Parnell of the University of Aberdeen, UK, and his colleagues found sulphides, apparently formed through microbial activity, permeating the rocks of Haughton crater in the Canadian Arctic.

An analysis of the crater’s rocks indicates the sulphides were produced at temperatures above 70 degree Celsius.

That suggests they formed shortly after the crater itself was created by a meteorite impact 39 million years ago, when water warmed by the impact would have circulated through the crater rocks.

Despite the passage of time, the signature of life at Haughton crater remains clear, with sulphur-34 depleted by 7 per cent in the sulphides compared with the sulphates.

“This suggests that such a signature is not easily erased, bolstering the chances that Martian rocks that were moist enough to harbour life long ago could still carry a detectable signature of life,” said Parnell.

NASA’s Mars Science Laboratory (MSL) rover will land on the Martian surface in 2012.

“It will carry a mass spectrometer that should be sensitive enough to see variations as small as 2 per cent in sulphur isotope abundances,” said John Grotzinger of the California Institute of Technology in Pasadena, the lead scientist for the mission.

Sulphur is “definitely a promising candidate” to reveal signs of life on Mars, according to David Des Marais of NASA’s Ames Research Center in Moffett Field, California, who is also involved in the mission.

“If there are big isotopic differences that would be very suspicious. The only way we know how to do that on Earth is with life,” he added. (ANI)

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Mars quite similar to planet Earth

July 3, 2009 By Leave a Comment

Washington, July 3 (ANI): A new research has determined that many characteristics of Mars are quite similar to planet Earth, including its landscape, history of water, soil and even its weather.

The research, by Mark Lemmon, a professor of atmospheric sciences, Texas A and M University, US, points out that last year’s Phoenix Mars Lander mission keeps revealing secrets about the planet, answering some questions but raising other big ones.

“Phoenix landed in a place that has access to Martian ice, which is exciting by itself,” Lemmon said of the Mars probe, which landed May 25, 2008.

The mission goals were to investigate the suitability of Mars for past or present life, but Phoenix was incapable of detecting life itself.

“Phoenix was designed to verify and investigate subsurface ice, and it found it almost instantly,” explained Lemmon. “The entire area where it landed has water ice just a few inches under the soil. The area is cold now, but it has been warmer in the past,” he added.

“No water in a liquid state has been found yet, but there is new evidence that Mars had liquid water billions of years ago,” said Lemmon.

Using its robotic arm, the Mars Lander was able to scoop up dirt, which was mixed with ice, and analyze it.

“Where it landed is a barren place that resembles the dry valleys of Antarctica. The area has mounds and troughs, and just like in Antarctic valleys, there is no liquid water but plenty of ice,” said Lemmon.

“Some of these patches are fairly pure. Others have the ice mixed with soil containing energy sources and nutrients that could be used if there were life,” he added.

According to Lemmon, the soil has perchlorate, a form of chlorine that is considered hazardous, but certain types of bacteria are able to live on it here.

“The interesting thing is, the soil has a potential energy source and oxygen source for life on Mars,” he said.

Traces of calcite were also found, which shows a presence of liquid water at some time in the past, Lemmon notes.

Phoenix also found weather patterns similar to those on Earth, including cold fronts that bring in gusty winds and sub-freezing temperatures.

Another bonus: Phoenix saw small Martian snowflakes, which leads the team to believe that snowfall on Mars was once a common occurrence.

“To sum it up, we found a place on Mars that is similar to cold, dry environments on Earth, and those environments are capable of supporting life,” Lemmon explained. (ANI)

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NASA robots may be destroying signs of life on Mars

May 25, 2009 By Leave a Comment

London, May 25 (ANI): NASA’s robot explorers may have been destroying the signs of life on Mars, say researchers.

When the twin Viking landers, sent on the planet in 1976, failed to detect even minute quantities of organic compounds, scientists were puzzled because even if Mars has never had life, comets and asteroids that have struck the planet should have scattered at least some organic molecules – though not produced by life – over its surface.

Many scientists have suggested that organics were cleansed from the surface by naturally occurring, highly reactive chemicals such as hydrogen peroxide.

Even last year, NASA’s Phoenix lander, also failed to detect organics on Mars, but it did stumble on something in the Martian soil that could have been hiding the organics-a class of chemicals called perchlorates.

Perchlorates, are relatively harmless at low temperatures, but when heated to hundreds of degrees Celsius they release a lot of oxygen, which tends to cause any nearby combustible material to burn.

Both the Phoenix and Viking landers searched for organic molecules by heating soil samples to similarly high temperatures to evaporate them and analyse them in gas form.

Douglas Ming of NASA’s Johnson Space Center in Houston, Texas, and colleagues tried heating organics and perchlorates like this on Earth, he found that the resulting combustion left no trace of organics behind.

Chris McKay of Ames said that iron oxides have also been suspected of interfering with the detection of organics, but perchlorates are probably far more effective.

He added that even if organics make up a few parts per thousand of the soil, Viking or Phoenix could have missed them, thus it is too soon to conclude that these materials are not there.

“We haven’t looked the right way,” he said.

Organic chemicals are not the only substance that mars robots may have missed on the Red Planet, they could have even missed out on carbonate salts littering the surface.

The researchers presented their results at the recent Lunar and Planetary Science Conference in Houston. (ANI)

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Methane-producing mineral discovered on Mars

March 28, 2009 By Leave a Comment

London, March 28 (ANI): Scientists have reported the discovery of a methane-producing mineral on Mars.

According to a report in Nature News, the evidence for the existence of the mineral, known as serpentine, was found by Bethany Ehlmann, a PhD student at Brown University in Providence, Rhode Island.

Ehlmann used a spectrometer on the Mars Reconnaissance Orbiter to identify two small outcrops of the mineral.

Serpentine arises from another mineral, olivine, in a hydrothermal process in which hydrogen gas is produced – a potential energy source for microbes that could in turn produce methane.

The process of serpentinization also produces methane itself, without the need for life. “It was a past source of methane, for sure,” said Ehlmann.

Serpentine can also be altered, in lower temperature water, into carbonate.

However, the finding does not rule out life on Mars today. That depends on whether the presence of serpentine has anything to do with the apparent production of present-day methane.

“It’s certainly an intriguing coincidence that one of the major regions in which we find these minerals has been highlighted as a possible source region of methane. But, there’s this timing problem,” said Ehlmann.

The problem of timing arises because serpentine on Mars is ancient, about 3.8 billion years old, whereas the reports of methane gas are contemporary.

Yet it is possible, according to Ehlmann, that fractures deep underground could be providing the necessary water and heat for serpentine to be formed today, and for methane to percolate up. (ANI)

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