Perseverance rover detects complex carbon molecules on
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- Perseverance rover detected macromolecular carbon (MMC) in mudstones at the Bright Angel outcrop along Neretva Vallis, a dried-up ancient river channel flowing into Jezero crater billions of years ago.
- The rover's Sherloc instrument identified the organic carbon by firing an ultraviolet laser at rocks and analyzing scattered light, finding MMC on the surface of the Cheyava Falls mudstone.
- Macromolecular carbon can originate from biological sources such as fossilized microbial mats and coal, but also from non-biological processes including water-rock reactions and meteorite impacts, so the detection does not constitute proof of past Martian life.
- Then-acting NASA head Sean Duffy called the same Bright Angel mudstones' 2024 "leopard spot" features "the clearest sign of life that we've ever found on Mars" when those surface textures were published last year.
- Organic-bearing mudstones have now been identified more than 2,000 miles apart on Mars — by Perseverance in Jezero crater and by Curiosity in Gale crater — suggesting habitability and the availability of organics were widespread billions of years ago.
- Co-author Kyle Uckert of NASA's Jet Propulsion Lab said Perseverance's payload cannot distinguish biotic from abiotic origins and that "the best way to determine the biogenicity of these rocks is to conduct these follow-up analyses on Earth" after sample return.
- NASA's Mars sample return mission was effectively scrapped in January, with a revised mission now planned for the 2030s; China is targeting 2031 for its own Martian sample return.
Why it matters: Confirming whether these carbon molecules came from ancient microbes requires Earth-based laboratory analysis — but NASA scrapped its sample return mission in January and a replacement isn't expected until the 2030s, meaning the rocks may sit on Mars for years while China targets a 2031 return of its own.
