Rock samples collected recently from Mars may hold definitive proof of life on the red planet. The NASA Perseverance Rover made waves this week after visiting a dry river channel in the Jezero Crater. The “potential biosignature” uncovered by the six-wheeled spacecraft will require laboratory analysis before it can be confirmed. Perseverance has made several new discoveries since its 2021 landing within the ancient Martian lake — finding multiple signs of organic material in the area.
“After a year of scientific scrutiny, a rock sample collected by the Perseverance rover has been confirmed to contain a potential biosignature. The sample is the best candidate so far to provide evidence of ancient microbial life on Mars,” NASA wrote on X.
The space agency explained that its rover had discovered the rock formation in an ancient, now-dry riverbed within the Jezero Crater. Instruments revealed that it was composed of clay and silt — both “excellent preservers of past microbial life” on Earth. An official confirmation can only be issued after in-depth analysis of the sample gathered by Perseverance — ideally in terrestrial labs.
How does the rover ‘detect’ life?
A potential biosignature is any substance or structure that might have a biological origin but requires more data or further study before a conclusion can be reached. The sample — called Sapphire Canyon — was collected from a rock named Cheyava Falls last year. Acting NASA Administrator Sean Duffy said this finding was “the closest we have ever come to discovering life on Mars”.
The Perseverance rover cannot directly detect life on the red planet during its travels. Instead it carries a drill to penetrate rocks and tubes to hold the samples gathered from places judged most suitable for hosting life billions of years ago. The samples are awaiting retrieval to Earth — an ambitious plan that’s on hold as NASA seeks cheaper, quicker options.
Two scientists not involved in the study told AP News that it was an “exciting discovery” but warned that non-biological processes could be responsible.
“That’s part of the reason why we can’t go so far as to say, A-ha, this is proof positive of life. All we can say is one of the possible explanations is microbial life, but there could be other ways to make this set of features that we see,” Joel Hurowitz of Stony Brook University told The Associated Press.
Significance of the Jezero Crater
“Perseverance is exploring Jezero Crater, a location on Mars that shows promising signs of a place that was likely friendly to life in the distant past. The rover’s goal is to study the site in detail for its past conditions and seek the very signs of past life. It is carrying out its mission to identify and collect the most compelling rock cores and other samples of Mars material, which a future mission could retrieve and bring to Earth for more detailed study,” NASA explains in its Mission page for the rover.