On February 18, 2021, NASA Persistence rover placed on the surface of Mars. During the next two years of its primary mission, the robber will search the Jezero crater (where he ended up) for evidence of previous life on Mars. It will consist of the collection of soil and rock samples from the preserved delta feature formed billions of years ago from sediments deposited by flowing water.
The question is, where should it look for this possible evidence? A possible route the rover will take during its primary mission is shown in a series of recent images provided by NASA and the US Geological Survey (USGS). As illustrated in the image below, this path will take it from the cliffs that form the edge of the delta, up and across the surface to possible “coastal” deposits and up to the edge of the crater.
The Jezero crater was chosen as the landing site for the Persistence mission because scientists believe the area was once flooded with water. It was one of sixty candidate locations considered by a panel of mission team members and scientists from around the world. After five years of studying and exploring potential sites, Jezero is considered the most promising site.
This is because Jezero has several features that are believed to be the remains of ancient environments, some of which were presumably habitable at one time. Much like the storm surge crater, where the Curiosity rover (Persevrerance’s sister mission) landed in 2012, formed these features in the presence of water and thus provides clues to the past of Mars, which could periodically support flowing water.
The base of the delta’s cliff, for example, defines the outer edge of where sediments were deposited by the river that flowed into the crater billions of years ago (at a time when Mars was significantly warmer and had plenty of water on its surface). The surface of the delta and possible coastline are likely places to find fossilized bacteria, which will leave the rover in a closet for future recovery.
Meanwhile, the crater rim – which is 610 meters high – indicates the boundary of the ancient lake and it probably holds indications of the height of the lake over time. Once it gets there, Persistence will explore it and the surrounding plains to learn more about when the crater is a lake. It is also hoped that it will learn more about how and when the lake lost its water over time.
The trail is several tens of miles long and will keep the rover occupied for the duration of its primary mission. For reference, the prominent crater in the delta function (near the center of the image) is about 1 km (0.6 miles) in diameter. In the event of a mission expansion – which, except for any issues, seems very likely – the mission controllers will start looking for another promising path to follow.
Like its predecessors, Persistence can explore Mars for many years to come! But this mission will also carry out an unprecedented scientific operation, where the monsters it collects will be returned to Earth by a separate ESA mission. This will allow scientists to analyze rocks and soil from Mars in Earth laboratories for decades to come.
Like the lunar rocks returned by the Apollo astronauts, the study of these extraterrestrial materials will lead to breakthroughs in our understanding of how the rocky planets formed our solar system, and perhaps even how life on earth began (and possibly also on Mars). It promises to be an exciting time, so much for sure!
Further reading: NASA