NASA said its Mars Perseverance rover has collected rock-core samples in an area long considered by scientists to be a top candidate for finding signs of ancient microbial life.
In an update, the team said its latest findings provide greater detail of the region, with the rover taking four samples from an ancient river delta in the 28-mile-wide Jezero Crater since July.
In total, the rover has collected 12 compelling rock samples.
The crater’s delta formed about 3.5 billion years ago at the convergence of a Martian river and a lake.
The delta’s sedimentary rocks formed when particles of various sizes settled in the environment.
During its first scientific campaign, the rover explored the crater’s floor, finding igneous rock.
“We picked the Jezero Crater for Perseverance to explore because we thought it had the best chance of providing scientifically excellent samples – and now we know we sent the rover to the right location,” Thomas Zurbuchen, NASA’s associate administrator for science in Washington, said in a statement. “These first two science campaigns have yielded an amazing diversity of samples to bring back to Earth by the Mars Sample Return campaign.”
“The delta, with its diverse sedimentary rocks, contrasts beautifully with the igneous rocks – formed from crystallization of magma – discovered on the crater floor,” Perseverance project scientist Ken Farley said. “This juxtaposition provides us with a rich understanding of the geologic history after the crater formed and a diverse sample suite. For example, we found a sandstone that carries grains and rock fragments created far from Jezero Crater – and a mudstone that includes intriguing organic compounds.”
One of those rocks is “Wildcat Ridge,” which likely formed billions of years ago.
Perseverance has abraded some surface of the rock so it could analyze the area with its Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument.
NASA said the SHERLOC samples were found to feature a class of organic molecules that are spatially correlated with those of sulfate minerals.
The presence of organic molecules, which can contain elements like sulfur, is considered to be a potential biosignature.
While Perseverance and the Curiosity Mars rovers have found evidence or organics before, this detection was made in an area where sediment and salts were deposited into a lake under conditions in which life could have potentially existed.
“In the distant past, the sand, mud and salts that now make up the Wildcat Ridge sample were deposited under conditions where life could potentially have thrived,” Farley explained. “The fact the organic matter was found in such a sedimentary rock – known for preserving fossils of ancient life here on Earth – is important. However, as capable as our instruments aboard Perseverance are, further conclusions regarding what is contained in the Wildcat Ridge sample will have to wait until it’s returned to Earth for in-depth study as part of the agency’s Mars Sample Return campaign.”