( CNN ) -- It could be a sign , a vague one . A NASA rover has found the building blocks of life on Mars . They might be the product of past or present life on the Red Planet -- or they might not be . Either way , the samples of organic matter in the atmosphere and in rock show that Mars may at least have once had conditions favorable to hosting life , NASA said in a statement . They also show that the planet is still chemically active . The Curiosity rover 's tapping into organics in rock is the first find ever of life 's building blocks on Mars ' surface . Gas blast . The rover has run into pockets of gas on Mars : methane , often used to fire up gas stoves back on Earth . Organic matter is made up of carbon bonded with other elements , often hydrogen and oxygen . Living things are made up of it , but life is not necessary for it to exist . Methane is the smallest organic compound , consisting of one carbon and four hydrogen atoms . On our planet , methane is a fossil fuel , but it can also rise out of rotting sewage or fly through the air in flatulence . In other words , it usually comes from something living , or something that was once alive . No life found . That could be the case on Mars , too , NASA said in a statement this week . But the space agency carefully points out that methane can also come from inanimate sources as well . `` There are many possible sources , biological or non-biological , such as interaction of water and rock , '' said Sushil Atreya , a scientist on the Curiosity team . At this point , NASA does n't know if microbes are behind the gas or just minerals . Researchers used Curiosity 's instruments a dozen times to get a breath of methane , and four of those times , it peaked at a level 10 times higher than usual . They believe it may have been puffed up from the ground like little burps . Organic rock . Curiosity also found organic matter while drilling into stone . `` This first confirmation of organic carbon in a rock on Mars holds much promise , '' said scientist Roger Summons , who works on the rover team . These building blocks of life could have formed on Mars , or meteorites could have brought them there . Scientists are n't sure yet . Also , they ca n't be completely sure what molecules they are , because a coincidental chemical reaction that occurs in the detection device skews some of the samples . So far , they 've also found no sign of microbes in the rock powder , neither present nor past . The history of water on Mars has also been a popular research topic . The analysis of hydrogen atoms Curiosity found in rock have led NASA scientists to conclude that much of Mars ' former oceans disappeared very early -- before the rocks were formed .
The Curiosity rover found high levels of methane gas and other organic matter in rock . It could have been produced by microbes , but there is no concrete evidence of that . Comment: But existence of organic compounds on Mars are sign it may have supported life before .