NASA’s Perseverance rover may have found signs of ancient life on Mars

NASA’s Mars Jezero Crater investigation bears fruit

The Perseverance rover provided evidence last year that the Jezero Crater on Mars was once a lake with a connecting river delta. It was potentially the location of a rich, habitable environment some 3.5 billion years ago. In September last year, the rover scooped up its first sample, drilling 2 inches (6 cm) into the planet’s surface to extract a rock core, one of a number that will eventually be sent back to Earth.

The rover has now collected a total of 12 rock samples, and the latest is the most important yet, as NASA has identified organic molecules within the material it has extracted from the Martian surface.

Perseverance collected the sample on July 20 while investigating the sedimentary rocks of the twenty-eight-mile (45 kilometers) wide ancient river delta. The rover used its Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals, or SHERLOC, instrument to scan a sample collected from “Wildcat Ridge” on the river delta. The ridge is a rock approximately 3 feet (1 meter) wide that is thought to have formed billions of years ago due to mud and fine sand settling in an evaporating saltwater lake.

SHERLOC’s analysis shows the samples feature a class of organic molecules linked to sulfates. Crucially, sulfate minerals are capable of storing a significant amount of information about the watery environment in which they were formed.

“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,” explained Thomas Zurbuchen, NASA’s associate administrator for science in Washington. “These first two science campaigns have yielded an amazing diversity of samples to bring back to Earth by the Mars Sample Return campaign.”

NASA’s and ESA’s 2030s Mars Sample Return mission

It’s important to note, however, that not all organic molecules require life to form. This is due to the fact that some can be created through chemical processes.

Perseverance and the Curiosity rover have both found organic molecules in the past. The new sample finding is particularly significant, however, because it was discovered in a region that was targeted because life may have once existed there.

“The fact the organic matter was found in such a sedimentary rock — known for preserving fossils of ancient life here on Earth — is important,” said Perseverance project scientist Ken Farley of Caltech in Pasadena, California. “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.”

The key to uncovering the secrets of the Perseverance rover’s most recent sample lies in the Mars Sample Return campaign. The mission, which is being run by NASA and the ESA (European Space Agency), will develop multiple spacecraft and technologies in what NASA calls “one of the most ambitious endeavors in spaceflight history”.

The two agencies are designing rockets and autonomous systems that will be sent to Mars by around 2033 to retrieve the Perseverance samples and return them to Earth. NASA has announced it is already planning to deposit select sample tubes near the base of the delta in about two months. They will lie there for years, waiting for retrieval and then analysis here on Earth. The secrets they reveal could greatly alter our understanding of our place in the cosmos.