At a Glance

NASA's Curiosity rover has discoveredcomplex organic moleculeson Mars that may provideproof that"the planet could have supported ancient life."In an odd twist of fate, NASA says the same discovery may have occurred 40 years ago.However, a Viking probe likely burned up the evidence.

A NASA rover has recently discovered organic material that could confirmproof of life on Mars, but it's a discovery that may not necessarily be new.

In a study published last month in the journal Science, NASA reported that itsCuriosity rover hadcomplex organic moleculeson the Red Planet that may provideproof that"the planet could have supported ancient life."

On Tuesday, New Science noted that it is likely one or both ofcame across the very same evidence years ago. Unfortunately, the rovers apparently burned up the evidence and it took another 40 years before more evidence wasfound.

In the paper, lead author Chris McKay of NASA's Ames Research Center in Silicon Valley suggests the evidence may have beenlost when the Viking landers tested soil samples. It was practice for the rovers to heat the samples to release vapors for further analysis. However, this technique likely ignited a flammable salt called perchlorate, which destroyed the ancient organic matter.

More recently, the Curiosity rover discovered traces ofchlorobenzene in some soil samples. It is a compound produced only when carbon molecules burn with the flammable salt.

The discovery not only confirms the discovery of organic material that could be proof of lifebut that previous evidence was likely destroyed some 40 years ago when the soil samples were heated up by the rovers.

NASA has kept the June discovery of organic material rather quiet, primarily because they still are not sure of the origin of the organic materials and don't want to jump to conclusions that it is conclusive proof of life.

"Are there signs of life on Mars?We don't know, but these results tell us we are on the right track,"Michael Meyer, lead scientist for NASA's Mars Exploration Program, said in June.

Thomas Zurbuchen, theassociate administrator for the agency's Science Mission Directorate, that thediscoveries should be regarded as Mars "telling us to stay the course and keep searching for evidence of life."

"I'm confident that our ongoing and planned missions will unlock even more breathtaking discoveries on the Red Planet," he said.