Finding evidence of ancient life on Mars may be trickier than we thought. Image Credit: NASA
NASA's Curiosity rover has discovered that evidence of ancient life on the Red Planet may have been scrubbed.
There's nowhere beyond the Earth more tantalizing in the search for evidence of ancient alien life than Mars - a world that was once very much like our own planet with oceans, lakes and rivers.
While today it is an arid, desolate place, scientists have long hoped that evidence of its watery past - and the organisms that may have thrived during that time - can still be found there.
Now though, a new study has revealed that at least some of the potential evidence of past life on Mars may have been erased through geological processes that may be common across the planet.
Clay is often seen as a valuable material in the search for evidence of life - both because it forms when rocky minerals weather away after contact with water and because it is also good at preserving microbial fossils.
When Curiosity recently took samples from ancient mudstone at the site of a dried-up lakebed, however, some of it contained significantly fewer clay minerals that would be expected.
Scientists now believe that brine - which is essentially very salty water - may have leaked into the clay layers and destabilized them, wiping away potential signs of biological life.
"We used to think that once these layers of clay minerals formed at the bottom of the lake in Gale Crater, they stayed that way, preserving the moment in time they formed for billions of years," said study lead author Tom Bristow.
"But later brines broke down these clay minerals in some places - essentially resetting the rock record."
Source: Live Science | Comments (1)
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