Tiny Tunnels in Mars Rock Hint at Possibility of Life
What I find fascinating about this article is the fact that they looked for DNA in an object that came from Mars! That means that DNA, which I thought only was found in Earth-based life, must be a building block found thoughout the entire universe!
SPACE.com -- Tiny Tunnels in Mars Rock Hint at Possibility of Life
A study of a meteorite that fell in Egypt nearly 95 years ago may offer clues as to the search for possible life on Mars.
Researchers studying the meteorite that originated from Mars found a series of microscopic tunnels within the object that mimic the size, shape and distribution to tracks left on Earth rocks by the feeding frenzy of bacteria.
The discovery of the tiny burrows adds intrigue to the search for life beyond Earth. However, no DNA could be extracted from the meteorite, so it's not known if the tunnels are of biological origin. The scientists said the lack of DNA also does not derail the prospect.
[...] Scientists have dated the igneous rock fragment from Nakhla at 1.3 billion years in age. They believe that the rock was exposed to water about 600 million years ago, based on the age of clay found inside the rocks.
"Virtually all of the tunnel marks on Earth rocks that we have examined were the result of bacterial invasion," Fisk explained in an OSU press statement. "In every instance, we've been able to extract DNA from these Earth rocks, but we have not yet been able to do that with the Martian samples."
That being the case, there are two likely scenarios.
"One is that there is an abiotic [non-living] way to create those tunnels in rock on Earth, and we just haven't found it yet," Fisk said. "The second possibility is that the tunnels on Martian rocks are indeed biological in nature, but the conditions are such on Mars that the DNA was not preserved."
Fisk said it is commonly believed that water is an essential ingredient for life. "So if bacteria laid down the tunnels in the rock when the rock was wet, they may have died 600 million years ago. That may explain why we can't find DNA—it is an organic compound that can break down."