Intense heat during meteor impacts forged tiny bits of glass that trapped fragments of ancient plant life in Argentina. The same process may have entombed signs of life on Mars.
Geologists recently found plant shreds dating to 3 and 9 million years ago within meteor impact glass. The rapid encapsulation preserved intricate details of the plants' structure along with traces of organic chemical compounds.
Even tiny bumps, called papillae, on the leaves' surfaces were preserved. Some plant samples closely resembled pampas grass that still grows in the region. Geology Magazine published the report of this discovery.
The sandy, loose soil of a particular patch of Argentina proved perfect for producing meteor glass. Mars has a similar dusty surface. During an impact on Earth or Mars, intense heat melts silica, or sand, in the soil into blobs of glass. These blobs roll over living things and entrap fragments, similarly to how leaves get stuck inside snowballs. Moisture in the outer layer of the plant insulates the interior.
"The outside of the leaves takes it for the interior," said study leader Brown University geologist Pete Schultz, in a press release. "It's a little like deep frying. The outside fries up quickly but the inside takes much longer to cook."
Although astronaut paleontologists probably won’t find mummified Martian plant life within impact glass, microorganisms could have left tell-tale organic chemical signatures, suggested the study's authors.
Top photo: Gullies eroded into the wall of a meteor impact crater on Mars. Credit: NASA, JPL, Malin Space Science Systems, Wikimedia Commons. Bottom photo: A fragment of ancient plant life trapped in meteor impact glass. Credit: Brown University