“We’re speculating that you perhaps cannot find organics on the surface of Mars. You have to be below the surface or inside sedimentary rocks,” the New Scientist quoted Sam Kounaves of the Tufts University in Medford, Massachusetts, as saying.
Kounaves and colleagues studied a Martian meteorite called EETA 79001, collected in 1979 in Antartica where it fell 12,000 years ago.
The team found a white substance nestled in the meteorite that turned out to contain a form of nitrate, a chemical that some earthly bacteria use as fuel.
The Phoenix Mars lander had earlier found related compounds called perchlorates, which can also be fuel for microorganisms, in Martian soil.
The finding suggests that NASA’s Curiosity rover had to drill beneath the Martian surface to find traces of past.
Good news is Curiosity has brought along a drill.
Although it can only get 6.4 cm deep, scientists say it may be enough to find any organics preserved in rocks below.