Have signs of Martian life been obliterated by meteorite blasts? Extreme pressures during impact may wipe out organic compounds, study finds
Signs of life may be buried deep beneath the Martian surface, where organic compounds are protected from solar radiation and the harsh chemical processes above. To access these materials, scientists have analyzed rock samples that have been blasted to the surface by meteorite impacts – but so far, the results have been inconclusive. Now, researchers say the nature of these blasts may incorrectly imply the absence of life, wiping out any signs that may once have been there.
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| Martian Craters |
Scientists have analyzed rock samples from Mars that have been blasted to the surface by meteorite impacts, but so far, the results have been inconclusive. Now, researchers say these blasts may wipe out any signs that may once have been there.
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| Mars |
In a study published to the journal Scientific Reports, researchers from Imperial College London and the University of Edinburgh replicated meteorite blasts in the lab, focusing on those produced by meteorites roughly 10 meters in size. The team subjected different types of organic matter to extreme pressure and temperature in a piston cylinder device. Then, they used a pyrolysis-gas chromatography mass spectrometry to conduct a chemical analysis. This revealed that pressure from the impact destroyed long chain hydrocarbon-dominated matter, the organic compounds found in microbial and algal life.
But, the organic compound found in plant matter – dominated by aromatic hydrocarbons – was mostly resistant to the pressures, though it experienced some chemical changes. The researchers say these findings could help to guide future missions to the best locations or blast types on Mars to search for life.
The researchers say these findings could help to guide future missions in the search for life on Mars. Moving forward, they will investigate the effects of a wide range of temperatures and pressures to find the specific conditions that would allow organic material to survive.
HAS ALIEN LIFE GONE EXTINCT?
Researchers based at the Australian National University argue that life may well have emerged multiple times on other planets following the heavy bombardment of wet rocky worlds by asteroids. But they said almost all of this life would go rapidly go extinct unless it was able to evolve fast enough to regulate greenhouse gases and so maintain stable surface temperatures. While many planets could have potentially been habitable, and may have once teemed with microbial life, they argue, runaway heating or cooling would have left their surfaces inhospitable. The researchers say that while both Mars and Venus may once have been planets that could have hosted life four billion years ago, any life there failed to stabilise the environment. This resulted in Mars becoming a frigid desert while Venus became a boiling hothouse. Moving forward, the researchers will investigate the effects of a wide range of temperatures and pressures. Doing this would help them to find the specific conditions that would allow organic material to survive a blast. ‘The study is helping us to see that when organic matter is observed on Mars, no matter where, it must be considered whether the sample could have been affected by the pressures associated with blast impacts,’ says Dr. Wren Montgomery, co-author of the study from the Department of Earth Science and Engineering. ‘We still need to do more work to understand what factors may play an important role in protecting organic compounds from these blast impacts. ‘However, we think some of the factors may include the depths at which the rock records are buried and the angles at which meteorites hit the Martian surface'.
SEARCHING FOR ALIEN LIFE
In the search for alien life, scientists have analyzed rock samples that have been blasted to the Martian surface by meteor impacts. It's thought that these rocks, which originate from beneath the surface, may contain organic compounds. Buried underground, the compounds would be protected from solar radiation and the harsh chemical processes above. But in the new study, researchers found that the meteorite blasts which carry the rocks to the surface may also destroy any evidence of life.
By CHEYENNE MACDONALD
