
Martian organics in ancient rock fuel life-signs debate
A NASA-led analysis of long-chain organic molecules found in the Cumberland mudstone sampled by the Curiosity rover suggests the organics could plausibly arise from biological processes. While nonbiological explanations were increasingly unlikely, the researchers stop short of proving past life on Mars, noting that larger molecules and definitive biosignatures may require Earth-based experiments and a future Mars sample-return mission.