Molecules containing large chains of carbon and hydrogen--the building blocks of all life on Earth--have been the targets of missions to Mars from Viking to the present day. While these molecules have previously been found in meteorites from Mars, scientists have disagreed about how this organic carbon was formed and whether or not it came from Mars.
A new study led by the Carnegie Institute's Andrew Steele provides strong evidence that this carbon did originate on Mars, although it is not biological. These findings give researchers insight into the chemical processes taking place on Mars and will help aid future quests for evidence of ancient or modern Martian life.
There has been little agreement among scientists about the origin of the large carbon macromolecules detected in Martian meteorites. Theories about their origin include contamination from Earth or other meteorites, the results of chemical reactions on Mars, or that they are the remnants of ancient Martian biological life.