New evidence that microbes played a role in mysterious marks on Mars

Scientists reduce the explanations for a potential chemical of ancient life on Mars. This sign – brands found on Martian rocks last year – could have been caused by microbes or by a reaction that only takes place at high temperatures. New results suggest that the biological explanation is more likely.

Last year, while exploring an old lake bed called Bright Angel in the Jezero Mars crater, NASA's perseverance discovered a rock with unusual marks – called “Leopard …