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We may all be Martians

“Evidence is building that Earth life originated on Mars and was brought to this planet aboard a meteorite, said biochemist Steven Benner of The Westheimer Institute for Science and Technology in Florida.

An oxidized form of the element molybdenum, which may have been crucial to the origin of life, was likely available on the Red Planet’s surface long ago, but unavailable on Earth, said Benner, who presented his findings today (Aug. 28; Aug. 29 local time) at the annual Goldschmidt geochemistry conference in Florence, Italy.

…It’s only when molybdenum becomes highly oxidized that it is able to influence how early life formed,” Benner said in a statement. “This form of molybdenum couldn’t have been available on Earth at the time life first began, because 3 billion years ago, the surface of the Earth had very little oxygen, but Mars did. It’s yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet.”


Life possible on ‘large parts’ of Mars: study

“Australian scientists who modelled conditions on Mars to examine how much of the red planet was habitable said Monday that “large regions” could sustain life.”

Did a Colossal Asteroid Impact Deep Enough to Swallow Mount Everest Erase Mar’s Magnetic Field?

NASA Spacecraft Data Suggest Water Flowing On Mars

NASA Spacecraft Data Suggest Water Flowing On Mars – NASA Astrobiology

Are you a Martian? We all could be, scientists say – and new instrument might provide proof

March 23, 2011 – Original Source: PhysOrg

Are we all Martians? According to many planetary scientists, it’s conceivable that all life on Earth is descended from organisms that originated on Mars and were carried here aboard meteorites. If that’s the case, an instrument being developed by researchers at MIT and Harvard could provide the clinching evidence.

In order to detect signs of past or present life on Mars — if it is in fact true that we’re related — then a promising strategy would be to search for DNA or RNA, and specifically for particular sequences of these molecules that are nearly universal in all forms of terrestrial life. That’s the strategy being pursued by MIT research scientist Christopher Carr and postdoctoral associate Clarissa Lui, working with Maria Zuber, head of MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS), and Gary Ruvkun, a molecular biologist at the Massachusetts General Hospital and Harvard University, who came up with the instrument concept and put together the initial team. Lui presented a summary of their proposed instrument, called the Search for Extra-Terrestrial Genomes (SETG), at the IEEE Aerospace Conference this month in Big Sky, Mont.

The idea is based on several facts that have now been well established. First, in the early days of the solar system, the climates on Mars and the Earth were much more similar than they are now, so life that took hold on one planet could presumably have survived on the other. Second, an estimated one billion tons of rock have traveled from Mars to Earth, blasted loose by asteroid impacts and then traveling through interplanetary space before striking Earth’s surface. Third, microbes have been shown to be capable of surviving the initial shock of such an impact, and there is some evidence they could also survive the thousands of years of transit through space before arriving at another planet.

So the various steps needed for life to have started on one planet and spread to another are all plausible. Additionally, orbital dynamics show that it’s about 100 times easier for rocks to travel from Mars to Earth than the other way. So if life got started there first, microbes could have been carried here and we might all be its descendants.

So what?

If we are descendants from Mars, there might be important lessons to be learned about our own biological origins by studying biochemistry on our neighbor planet, where biological traces erased long ago here on Earth might have been preserved in the Martian deep freeze.

The MIT researchers’ device would take samples of Martian soil and isolate any living microbes that might be present, or microbial remnants (which can be preserved for about up to a million years and still contain viable DNA), and separate out the genetic material in order to use standard biochemical techniques to analyze their genetic sequences.

“It’s a long shot,” Carr concedes, “but if we go to Mars and find life that’s related to us, we could have originated on Mars. Or if it started here, it could have been transferred to Mars.” Either way, “we could be related to life on Mars. So we should at least be looking for life on Mars that’s related to us.”

Even a few years ago, that might have seemed like more of a long shot, but recent Mars orbiter and rover missions have clearly shown that Mars once had abundant water, and many of the conditions thought to be needed to support life. And although the surface of Mars today is too cold and dry to support known life forms, there is evidence that liquid water may exist not far below the surface. “On Mars today, the best place to look for life is in the subsurface,” Carr says.

So the team has been developing a device that could take a sample of Martian soil from below the surface — perhaps dredged up by a rover equipped with a deep drill — and process it to separate out any possible organisms, amplify their DNA or RNA using the same techniques used for forensic DNA testing on Earth, and then use biochemical markers to search for signs of particular, genetic sequences that are nearly universal among all known life forms.

The researchers estimate that it could take two more years to complete the design and testing of a prototype SETG device. Although the proposed device has not yet been selected for any upcoming Mars mission, a future mission with a lander or rover equipped with a drill could potentially carry this life-detection instrument.

No instrument has been sent to Mars specifically to look for evidence of life since NASA’s twin Viking landers in 1976, which produced tantalizing but ambiguous results. An instrument on the Mars Science Lander to be launched in the fall will investigate chemistry relevant to life. The instrument from the MIT-Harvard team directly addresses Earth-like molecular biology.

Christopher McKay, an astrobiologist at NASA-Ames Research Center in California who specializes in research related to the possibility of life on Mars, says this work is “very interesting and important.” He says, “it is not implausible that life on Mars will be related to life on Earth and therefore share a common genetics. In any case it would be important to test this hypothesis.” But he adds that there is another motive for doing this research as well: “From an astronaut health and safety point of view and from a return-sample point of view, there is more to worry about” if there are organisms closely related to us on Mars, since a microbe that is similar is much more likely to be infectious to terrestrial life forms than would a totally alien microbe — so it is very important to be able to detect such life forms if they are present on Mars. In addition, this method could also detect any biological contamination on Mars that has been brought by spacecraft from Earth.

This kind of test is something we have the ability to do, he says, and therefore, although such an experiment has not yet been formally approved, “it seems improbable to me that we will do a serious search for life on Mars and not do this test.”

This story is republished courtesy of MIT News (, a popular site that covers news about MIT research, innovation and teaching.

Provided by Massachusetts Institute of Technology

More Evidence for Widespread Water on Early Mars

June 27, 2010 – Original Source: Astrobiology Magazine

New evidence supports theories that conditions favorable for life may have existed all over the surface of ancient Mars. ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter have identified hydrated silicate minerals in the northern lowlands of Mars, indicating that water once flowed there.

Conditions favorable to life may once have existed all over Mars. Detailed studies of minerals found inside craters show that liquid water was widespread, not only in the southern highlands, but also beneath the northern plains.

ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter have discovered hydrated silicate minerals in the northern lowlands of Mars, a clear indication that water once flowed there.

The spacecraft have previously discovered thousands of small outcrops in the southern hemisphere where rock minerals have been altered by water. Many of these exist in the form of hydrated clay minerals known as phyllosilicates, and indicate that the planet’s southern hemisphere was once much warmer and wetter than it is today.

However, until this week, no sites with hydrated silicate minerals had been found in the northern lowlands, where thick blankets of lava and sediments up to several kilometers thick hamper efforts to probe the underlying bedrock.

The first hints that there may be hydrated silicates beneath the northern plains were provided by Mars Express’ OMEGA sensor. However, the outcrops were small and more detailed observations were required to confirm their presence. The OMEGA team sifted higher resolution data from a sensor on NASA’s orbiter.

Lyot crater is 210km in diameter. The blue lines show data taken by the Mars Express OMEGA sensor. The red boxes show the NASA CRISM pointings. The asterisks show the locations where hydrated minerals were detected. Credits: NASA/ESA/JPL-Caltech/JHU-APL/IAS

Their search concentrated on 91 sizeable impact craters where incoming asteroids had punched down several kilometers, exposing ancient crustal material. As reported this week in the journal Science, at least nine craters were found to contain phyllosilicates or other hydrated silicates.

These minerals, which formed in wet environments on the surface or underground, were identical to those found in the southern hemisphere.

“We can now say that the planet was altered on a global scale by liquid water more than 4 billion years ago,” says John Carter, University of Paris, the report’s lead author.

With the small sample of widely scattered sites, it is difficult to draw conclusions about the type of environment all that time ago. However, the nature and locations of the minerals provide some clues.

“They are rich in iron and magnesium, but less in aluminum. Together with the close proximity of olivine, which is easily modified by water, this indicates that the exposure to water lasted only tens to hundreds of millions of years,” says Jean-Pierre Bibring, the OMEGA Principal Investigator from the University of Paris.

Although Mars’ potential habitability did not last long, remarkably its record is still preserved in phyllosilicate-rich spots.

A number of scientists have suggested that a shallow ocean subsequently covered the lava-coated northern plains. However, no evidence in support of this is provided by the new results.

“Our studies do not find any signs of the lava plains in the north being altered by water,” says Dr. Bibring.

Mars is coloured by its elevation. The blue areas are the lower lying plains of the northern hemisphere. Lyot crater is marked with a box.
Credits: MOLA Science Team, NASA

On a positive note, the new results may suggest sites for future landers because evidence for water during the early history of Mars suggests that conditions may have been favorable for the evolution of primitive life.

Ocean Covered One-Third of Mars

2010.06.16 – Original Source: Astrobiology Magazine

A new study shows that a vast ocean likely covered one-third of the surface of Mars 3.5 billion years ago. If liquid water was present on ancient Mars, it is possible that habitats for life persisted as well.

A vast ocean likely covered one-third of the surface of Mars some 3.5 billion years ago, according to a new study conducted by University of Colorado at Boulder scientists.

The CU-Boulder study is the first to combine the analysis of water-related features including scores of delta deposits and thousands of river valleys to test for the occurrence of an ocean sustained by a global hydrosphere on early Mars. While the notion of a large, ancient ocean on Mars has been repeatedly proposed and challenged over the past two decades, the new study provides further support for the idea of a sustained sea on the Red Planet during the Noachian era more than 3 billion years ago, said CU-Boulder researcher Gaetano Di Achille, lead author on the study.

An illustration of what Mars might have looked like some 3.5 billion years ago when an ocean likely covered one-third of the planet’s surface, according to a new University of Colorado at Boulder study. Credit: Illustration by University of Colorado

A paper on the subject authored by Di Achille and CU-Boulder Assistant Professor Brian Hynek of the geological sciences department appears in the June 13 issue of Nature Geoscience. Both Di Achille and Hynek are affiliated with CU-Boulder’s Laboratory for Atmospheric and Space Physics. The study was funded by NASA’s Mars Data Analysis Program.

More than half of the 52 river delta deposits identified by the CU researchers in the new study — each of which was fed by numerous river valleys — likely marked the boundaries of the proposed ocean, since all were at about the same elevation. Twenty-nine of the 52 deltas were connected either to the ancient Mars ocean or to the groundwater table of the ocean and to several large, adjacent lakes, Di Achille said.

The study is the first to integrate multiple data sets of deltas, valley networks and topography from a cadre of NASA and European Space Agency orbiting missions of Mars dating back to 2001, said Hynek. The study implies that ancient Mars probably had an Earth-like global hydrological cycle, including precipitation, runoff, cloud formation, and ice and groundwater accumulation, Hynek said.

The study is the first to integrate multiple data sets of deltas, valley networks and topography from a cadre of NASA and European Space Agency orbiting missions of Mars dating back to 2001, said Hynek. The study implies that ancient Mars probably had an Earth-like global hydrological cycle, including precipitation, runoff, cloud formation, and ice and groundwater accumulation, Hynek said.

Di Achille and Hynek used a geographic information system, or GIS, to map the Martian terrain and conclude the ocean likely would have covered about 36 percent of the planet and contained about 30 million cubic miles, or 124 million cubic kilometers, of water. The amount of water in the ancient ocean would have formed the equivalent of a 1,800-foot, or 550-meter-deep layer of water spread out over the entire planet.

A number of scientists have proposed that the lowlands of Mars’s northern hemisphere were once covered in water. A region of possible shoreline near the giant volcano Olympus Mons has been photographed in detail by the Viking spacecraft and by the Mars Orbiter Camera. Credit: NASA

The volume of the ancient Mars ocean would have been about 10 times less than the current volume of Earth’s oceans, Hynek said. Mars is slightly more than half the size of Earth.

The average elevation of the deltas on the edges of the proposed ocean was remarkably consistent around the whole planet, said Di Achille. In addition, the large, ancient lakes upslope from the ancient Mars ocean likely formed inside impact craters and would have been filled by the transport of groundwater between the lakes and the ancient sea, according to the researchers.

A second study headed by Hynek and involving CU-Boulder researcher Michael Beach of LASP and CU-Boulder doctoral student Monica Hoke being published in the Journal of Geophysical Research-Planets — which is a publication of the American Geophysical Union — detected roughly 40,000 river valleys on Mars. That is about four times the number of river valleys that have previously been identified by scientists, said Hynek.

The river valleys were the source of the sediment that was carried downstream and dumped into the deltas adjacent to the proposed ocean, said Hynek. “The abundance of these river valleys required a significant amount of precipitation,” he said. “This effectively puts a nail in the coffin regarding the presence of past rainfall on Mars.” Hynek said an ocean was likely required for the sustained precipitation.

“Collectively, these results support the existing theories regarding the extent and formation time of an ancient ocean on Mars and imply the surface conditions during the time probably allowed the occurrence of a global and active hydrosphere integrating valley networks, deltas and a vast ocean as major components of an Earth-like hydrologic cycle,” Di Achille and Hynek wrote in Nature Geoscience.

“One of the main questions we would like to answer is where all of the water on Mars went,” said Di Achille. He said future Mars missions — including NASA’s $485 million Mars Atmosphere and Volatile Evolution mission, or MAVEN, which is being led by CU-Boulder and is slated to launch in 2013 — should help to answer such questions and provide new insights into the history of Martian water.

The river deltas on Mars are of high interest to planetary scientists because deltas on Earth rapidly bury organic carbon and other biomarkers of life and are a prime target for future exploration. Most astrobiologists believe any present indications of life on Mars will be discovered in the form of subterranean microorganisms.

“On Earth, deltas and lakes are excellent collectors and preservers of signs of past life,” said Di Achille. “If life ever arose on Mars, deltas may be the key to unlocking Mars’ biological past.”

Hynek said long-lived oceans may have provided an environment for microbial life to take hold on Mars.

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