CORVALLIS, Ore., March 23 (UPI) -- The study of a meteorite from Mars has revealed microscopic tunnels similar to tracks left on Earth rocks by feeding bacteria.
Although unable to extract DNA from the Martian rocks, scientists say the finding nonetheless adds intrigue to the search for life beyond Earth.
Martin Fisk, a professor of marine geology at Oregon State University and lead author of the study, said the tiny burrows do not confirm there's life on Mars, nor does lack of DNA from the meteorite discount the possibility.
"Virtually all of the tunnel marks on Earth rocks that we have examined were the result of bacterial invasion," Fisk said. "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.
"There are two possible explanations," he added. "One is that there is an abiotic way to create those tunnels in rock on Earth, and we just haven't found it yet. 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."
The study appears in the journal Astrobiology.