NASA has announced that a sample collected on Mars by its Perseverance rover may contain evidence of ancient microbial life
Perseverance took the sample from a rock named Cheyava Falls in a dry riverbed in Jezero Crater last year.
The sample, called Sapphire Canyon, contains potential signs of life in the form of biosignatures, according to a paper published in the science journal Nature on Wednesday.
Later, higher-resolution images revealed a distinct pattern of minerals arranged into reaction fronts (points of contact where chemical and physical reactions occur), which NASA described as “leopard spots.”
“The spots carried the signature of two iron-rich minerals: vivianite (hydrated iron phosphate) and greigite (iron sulfide),” NASA said on Wednesday, adding that vivianite is often found on Earth in sediments, peat bogs, and around decaying organic matter.
NASA described the minerals as “a potential fingerprint for microbial life,” though cautioned that there are also “ways to produce them without biological reactions, including sustained high temperatures, acidic conditions, and binding by organic compounds.”
But tantalizingly, the rocks at Bright Angel show no evidence of having experienced high temperatures or acidic conditions, but it remains uncertain whether the organic compounds present could have catalyzed the reaction at low temperatures.
The discovery in these relatively young sedimentary rocks raises the possibility that Mars may have harbored life for a longer period, or later in the planet’s history, than previously believed.
NASA administrator Sean Duffy described the finding by Perseverance as “the closest we have ever come to discovering life on Mars,” adding, “The identification of a potential biosignature on the red planet is a groundbreaking discovery, and one that will advance our understanding of Mars.”
Commenting on what could be a significant breakthrough, Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters, said the U.S. space agency will share the data with the wider science community in a bid to confirm or refute its biological potential.
Perseverance arrived on Mars in spectacular fashion in February 2021 and has since been using its onboard science instruments to gather and analyze rock samples in the hunt for evidence of ancient microbial life. A later NASA mission will attempt to collect the rover’s samples and bring them to Earth for closer analysis in laboratory conditions.
Knowing if there was life on Mars would provide insights into the origins and evolution of life, including how habitable environments develop and persist on planets like Earth. It could also help us make better judgments about the likelihood of life existing in other parts of the universe.
