Get used to hearing the name “Jezero Crater.” It’s the landing site for NASA’s Mars 2020 rover. The 2020 rover is slated to launch in July 2020, and will land at Jezero Crater in February, 2021.
It’s pretty easy to see why NASA chose Jezero Crater for the next rover in their Mars Exploration Program (MEP). MEP is NASA’s long-term plan to explore Mars robotically. It includes rovers like Spirit, Opportunity, and MSL, the InSight Lander, orbiting spacecraft, and soon the 2020 rover.
The Mars Exploration Program is designed to understand:
- the formation and early history of Mars.
- the history of geological processes and climate that have shaped Mars.
- the potential for Mars to have hosted life.
- how humans can explore Mars in the future.
- how Mars and Earth differ.
Water, of course, is central to life as far as we know. And we know that Mars used to be a much wetter place, with huge oceans and systems of rivers and lakes. We know this because landers have found minerals on the Martian surface that only form in the presence of water. We also know it because we can see water channels, ancient river beds, alluvial fans, and other things from orbit.
Jezero Crater has been a scientific target for many years now. It was in the running to be MSL Curiosity’s landing site before Gale Crater was chosen. Now, Jezero Crater is back on the menu.
Jezero Crater is an ancient lake that formed inside an impact crater. Detailed study of the features of the lake led scientists to conclude that the lake is ancient and did not experience times when water went down. Due to its long lifespan as a lake, it’s possible that life may have developed in the lake. It’s possible, though not necessarily likely, that preserved signs of life are waiting to be discovered at Jezero Crater.
One of the 2020 rover’s goals is to look for signs of ancient life and habitability, (though NASA says they don’t presume that Mars did harbour life), so Jezero Crater is a good place to search. But another goal is to look for minerals that form in the presence of water, which should be plentiful if Jezero was indeed a long-lived lake.
Rover technology and the scientific instruments they can carry have come a long way. But they still have their limitations. A rover can never carry the same type of advanced laboratory equipment that scientists have access to here on Earth. For that reason, the 2020 rover has another objective: preparing samples.
The rover is tasked with collecting samples from Mars, then preparing them and leaving them for a future mission to collect and return to Earth. If this sounds ambitious, it is. But at some point, we need to get samples back to Earth.
Another objective of the 2020 rover is to demonstrate technology for further exploration of Mars. This includes an experiment to produce a small amount of oxygen from CO2. It’ll also try to locate a source of subsurface water. Obviously, the ability to get oxygen and water on Mars will aid human exploration enormously.
There are practical reasons for choosing Jezero Crater too. The rover needs a large enough area to land safely. Precision landing on Mars has come a long way, but the 2020 rover will use basically the same system the MSL curiosity did. But it still needs ample space to land, which Jezero provides. NASA would like to have a landing ellipse that is 20km x 25km.
The 2020 rover has a planned mission duration of one year, but that’s modest. If the success of Spirit, Opportunity, and MSL is any indication, the 2020 rover could be busy for years. And that means it may complete its exploration of Jezero Crater and have time on its hands.
Luckily, there are other sites nearby that are worth investigating. Scientists have discovered a large concentration of the mineral olivine near Nili Fossae, to the north of Jezero Crater. This area is within striking distance for the 2020 rover, and understanding the olivine deposit and the explosive volcanic activity that created it will help planetary scientists piece together early Mars’ water budget.
It’s only a little more than a year and a half before the 2020 rover sets down on Mars. We’ll have to endure the launch, the hopefully uneventful flight, and of course the anxiety-inducing landing sequence. But hopefully, if all goes well, the rover will be at Jezero Crater sending back images and data and making new discoveries.