Organic carbon molecules, which are molecules containing long chains of carbon and hydrogen, have previously been found on meteorites from Mars, but researchers have disagreed about where they were from and how they were formed. On Earth, these molecules are the building blocks of life.
Newly released research strongly suggests that this organic carbon did form on Mars, but not by biological processes.
The new findings give insight into the chemical processes taking place on Mars, and will help in the search for evidence of modern or ancient Martian biological life.
There had been little consensus on the origin of the organic carbon in the meteorites before this. Theories range from contamination by the Earth or other meteorites, to chemical reactions on Mars, to evidence of life on ancient Mars.
The research team examined 11 Martian meteorites whose ages span 4.2 billion years of history. Out of the 11, they detected large carbon molecules in 10 of them. The molecules were located inside grains of crystallized minerals.
Using an array of research techniques the researchers showed that at least some of the molecules were indigenous to the meteorites themselves.
The researchers next looked at the other minerals present with the carbon molecules to get an idea of the chemical processes that might have formed them. The grains enclosing the carbon provided evidence that the carbon was formed during volcanic processes, and that Mars has likely been doing organic chemistry throughout its history.
“These findings show that the storage of reduced carbon molecules on Mars occurred throughout the planet’s history and might have been similar to processes that occurred on the ancient Earth,” Steele said. “Understanding the genesis of these non-biological, carbon-containing macromolecules on Mars is crucial for developing future missions to detect evidence of life on our neighboring planet.”
Source: Carnegie Institution
Image Credits: NASA, Jet Propulsion Laboratory