After fooling around Jezero crater for 550 Martian days, NASA’s Perseverance rover has amassed almost half of its planned rock collection — including some containing organic molecules, a possible sign life could have thrived there more than 3 billion years ago. These are compounds containing carbon and often hydrogen or oxygen, which are likely critical to the origin of life.
“We have discovered rocks deposited in this lake in a potentially habitable environment and we have been looking for potential biosignatures” that may have been produced by life, Ken Farley, a scientist on the Perseverance project at Caltech, said earlier today a press conference at NASA’s Jet Propulsion Laboratory in Pasadena, California. In fact, the Perseverance team chose the crater as the rover’s landing spot for this very reason. It seems to be the site of an ancient river delta – a favorable place for microorganisms that arose and evolved long ago, and an attempt to finally answer the question, “Are we alone in the cosmos?”
Still, Farley points out, organic molecules could have been made in other ways—it’s also possible to make them by abiotic natural processes. But Percy, as the Rovers are sometimes called, cannot definitively pinpoint their origins. Because of this, NASA and the European Space Agency are planning a model return mission in the early 2030s to pick up a variety of rocks from the region and send them back to Earth.
The Perseverance team expects the rover to have a long lifespan, like its predecessor Curiosity, which is still in service. (Perseverance is actually NASA’s fifth rover to be deployed to the Red Planet.) Their preferred plan is for Perseverance to deliver the team’s favorite rock samples to a new lander equipped with a small rocket that will take the samples to an orbiter promoted who will do so then they fly to earth. If the mission goes as planned, the team will deliver the orbiter and lander from Earth to Mars in 2027 and 2028, respectively. The spacecraft loaded with rock samples will transport them to the western Utah desert in 2033.
NASA also has a backup plan. If anything happens to Percy in the next few years, the rover will also cache some samples in a safe, flat place where they can be easily retrieved. Since the planet has little weather and few major marsquakes that could damage the samples, the cache should be left untouched until the lander arrives. This mission will also include two helicopters – built like the Ingenuity plane already supporting Perseverance’s mission – which could be used to collect samples.
Mars is completely uninhabitable today. With very little of its atmosphere left, the planet is a cold, arid wasteland exposed to space radiation. However, scientists believe it could have been a much more hospitable place billions of years ago when it was more temperate and hosted flowing liquid water. This makes it the closest world to earth that could one day be inhabited – if only by microbes.