The crater is 45 km wide and once contained a river delta, with traces of images from the Mars Reconnaissance Orbiter.
In a study, researchers discovered the signature of carbonate minerals inside the crater rim. On Earth, carbonates are associated with shell, coral and stromatolite fossils found scattered on the ancient shores of ancient lakes and waters.
Scientists are fascinated by these carbonate deposits on the inner rim of Jezero because they seem to suggest that the carbonates are sitting on an ancient coast. The carbonates could also contain information about how Mars has transformed from habitable to inhospitable (the planet could once hold liquid water on the surface and maintain a thick atmosphere, but now it has an incredibly thin atmosphere and is a rough, icy and cold barren desert). ,
The 2020 Rover will be able to study these carbonates because its instruments are up to the task. Another rover, Curiosity, was designed to help scientists determine if Mars could have helped life in the past. The 2020 Rover continues this mission and hopes to find evidence of this potential ancient life. It will collect and store rocky core samples in metal pipes that can be returned by future missions.
"CRISM discovered carbonates here years ago, but we have recently noticed how concentrated they are right where a lake shore is," said Briony Horgan, principal author of Purdue University. "We will encounter carbonate deposits in many places during the mission, but the bathtub ring will be one of the most exciting places to visit."
The presence of carbonates is no guarantee that they came from the lake, as they could have existed there before the lake formed. However, it is worth exploring the site during the rover's two-year mission, which includes exploring the delta and bottom of the crater.
"The possibility of marginal carbonates forming in the marine environment was one of the most exciting features that led us to our landing site in Jezero." Carbonate chemistry on an old lakeshore is a fantastic recipe for keeping records of old life and life Climate, "said Ken Williford, associate Mars 2020 project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. "We are excited to get to the surface and find out how these carbonates have formed."
"Using a technique we have developed that helps us find rare, hard-to-detect mineral phases in data from orbiting spacecraft, we found two sites of hydrated silica in the Jezero Crater." said Jesse Tarnas, study author and doctoral student at Brown University. "We know from Earth that this mineral phase is exceptional for preserving microfossils and other biosignatures, making these outcrops into interesting targets for the rover."
The ancient delta is intriguing to scientists, as river deltas on Earth contain diverse material and can preserve signs of past life. The presence of the hydrated silicates in the delta makes it even more likely that the rover on Mars could find evidence of ancient life.
"The material that forms the lower layer of a delta is sometimes the most productive of biosignature conservation," said Jack Mustard, co-author and professor at Brown University. "So, if you find that there's a lot of silica in this bottom layer, that's a double bonus."
The Rover's instruments can detect whether the minerals have formed in the delta or whether they were carried in the watershed that fed the delta.
"We can get amazing high-resolution imagery and composition data from orbit, but there is a limit to what we can detect in terms of the formation of these minerals," Tarnas said. "With instruments on the rover, however, we should be able to limit the source of these deposits."
The Rover is also capable of performing chemical analyzes of minerals, linking its data with data from the orbiter, and even searching for these complex organic materials.
"If these deposits present in the form of rocks that are large and competent enough to drill into, they could be cached," Mustard said. "This work suggests that they are a great rehearsal."