NASA's Perseverance rover has uncovered its strongest evidence yet that Mars may once have supported life, and in rocks younger than scientists expected.
A paper published Wednesday in Nature details the discovery of potential biosignatures within a rock sample nicknamed 'Sapphire Canyon', drilled from a site known as 'Cheyava Falls' in July 2024. The find suggests that Mars could have remained habitable far later in its history than previously believed.
Signs of Life?
Potential biosignatures are substances or structures that may have a biological origin but require further analysis before confirming or rejecting life's presence.
'This finding by Perseverance is the closest we have ever come to discovering life on Mars,' said Acting NASA Administrator Sean Duffy. 'The identification of a potential biosignature on the Red Planet is a groundbreaking discovery, and one that will advance our understanding of Mars.'
Scientists say the sample contained organic carbon, sulfur, oxidized iron and phosphorous, elements crucial for life as we know it on Earth.
Instruments also detected unusual mineral patterns dubbed 'leopard spots', formed from iron-rich minerals such as vivianite and greigite. On Earth, these minerals can be linked to microbial activity.
Younger Rocks, Bigger Questions
The discovery was particularly striking because Cheyava Falls is composed of relatively young sedimentary rocks. Previous models assumed any traces of ancient life would be locked away in older formations.
'The combination of chemical compounds we found in the Bright Angel formation could have been a rich source of energy for microbial metabolisms,' said lead author Joel Hurowitz of Stony Brook University. 'This suggests that Mars may have supported life for a longer period than we imagined, or at a later stage in its history.'
Balancing Excitement With Caution
NASA scientists stressed that while the evidence is compelling, abiotic processes can also create the same mineral signatures.
'Astrobiological claims, particularly those related to the potential discovery of past extraterrestrial life, require extraordinary evidence,' said Katie Stack Morgan, Perseverance's project scientist at NASA's Jet Propulsion Laboratory.
The discovery's publication in a peer-reviewed journal ensures the data can now be scrutinized and tested by the global science community.
Looking Ahead
Perseverance has collected 27 rock cores since landing in Jezero Crater in February 2021. To confirm whether the potential biosignatures truly represent signs of ancient life, NASA and the European Space Agency plan to return selected samples to Earth through the Mars Sample Return mission.
'With each discovery, we get closer to answering the profound question: Are we alone?' said Nicky Fox, associate administrator of NASA's Science Mission Directorate. 'And this finding suggests Mars may have remained habitable much later than we thought.'
