Search for Signs of Ancient Martian Life

Mars 2020 is planned for launch in July 2020 aboard an Atlas V 541 Space Shuttle Complex 41 launch at the Cape Canaveral Air Force Station in Florida. The robot will conduct geological assessments of its landing site on Mars, determine the habitability of the environment, look for signs of life on ancient life and evaluate the natural resources and hazards. It will also prepare a collection of samples for a possible return to Earth for a future mission.

Director of the Jet Propulsion Laboratory Dr. Ken Williford said, “Previous missions to Mars have used a broad brush – analyzing average chemistry over roughly the size of a postage stamp – to ‘follow the water’ and seek ancient habitable environments. Mars 2020 takes the next step in its search for evidence of ancient microbial life, focusing measurements to the microbial scale and producing high-resolution maps over similarly small analytical areas. New scientific methods searching for ancient evidence of life on Earth have led to a leap in capabilities for biosignature detection. Instead of using ‘bulk’ geochemistry techniques that measure the average composition of a rock. The Mars 2020 mission is developing new capabilities including X-ray fluorescence and Raman spectroscopy in order to map the elemental, mineral and organic composition of rocks at a high spatial resolution. Understanding spatial distribution of chemical features preserved in ancient rocks the key to determining if they were formed by life. These new techniques allow exploration of Mars at telescopic to microscopic scales”.

Dr. Ken added, “Mars 2020 represents a crucial first step towards a possible Mars sample return. Our objective is to collect a diverse set of samples from our landing site with the best potential to preserve records of the evolution of Mars – including the presence of life if it was there. We’ll use our onboard instruments to provide the critical field context that future scientists would need to understand the measurements made back on Earth,” said Dr. Ken.

“We’ve got some hard decisions in front of us,” Dr. Ken said. “Because of the possibility of sample return, the selected site could have an outsized impact on the future of Mars science compared to a typical mission. We’ve been working hard to understand the scientific potential of the different sites and engaging the international scientific community for input on this consequential choice. The team is extremely excited about the opportunity to bring a powerful new payload to the surface of Mars and produce some spectacular results wherever we end up.”

Participants in a landing site workshop for NASA’s Mars 2020 mission have suggested three locations for further evaluation – Northeast Syrtis, Jezero crater, and Columbia Hills.

The Syrtis Northeast once warmed by volcanic activity. Underground heat sources have thrown hot and melting ice from the surface. Microbes can thrive here in liquid water that was in contact with minerals. The soil layers have a rich history of interactions between water and minerals during successive periods of early Mars history.

Jezero Crater tells a story of the naked and bare nature of the humid past on Mars. The water was drained and the crater was filled at least twice. There are more than 3.5 billion years, the riverbeds have spread into the crater wall and created a lake. Scientists see evidence that water carries the clay minerals from the surrounding area into the crater after drying the lake. It is conceivable that microbial life could live in Jezero for one or more of humid climates. If so, the signs of their remains could be found in the sediments of the lake.

In the Columbia hills, mineral springs have been tucked into the rocks. The discovery that the hot springs flowed here was a major achievement of the exploration of Mars, Spirit. The discovery that the rover was a pleasant surprise because the Spirit had not found traces of water around the Gusev crater 100 miles (160 kilometers). Once the vehicle has stopped operating in 2010, studies of its old data records showed that the floods of the past formed a shallow lake in Gusev.

NASA’s Jet Propulsion Laboratory to build and operate the Mars 2020 operations for the NASA Science Mission Directory at the headquarters in Washington

(Image Credit: NASA)