Natural Perseverance
NASA’s Perseverance rover has had a busy first month on Mars’s surface. From Jezero Crater, where Perseverance landed on 18 February, it has been doing as much geology as it can — snapping pictures of its surroundings and analysing the rocks nearby. Already, team scientists have determined that several of the rocks are chemically similar to volcanic rocks on Earth, and that wind and water have eroded some of them.
“Everything is going great so far,” said Kenneth Farley, a geochemist at the California Institute of Technology in Pasadena and the mission’s project scientist. He and others described Perseverance’s progress on 16 March at a virtual meeting of the Lunar and Planetary Science Conference.
As planned, the rover’s main science experiments will have to wait a few more months, while engineers continue to test its scientific instruments and prepare for the first helicopter flight on another world. Eventually, Perseverance will deploy an arsenal of tools, including a drill bit, a close-up camera and multiple chemical sensors to hunt for signs of past life in Martian rocks.
In the meantime, team scientists are plotting how the rover might travel from its landing site — recently named after the late science-fiction writer Octavia Butler — to the 40-metre-high cliffs of the ancient river delta that was the reason for Jezero’s choice as landing site in the first place. The delta, deposited billions of years ago by a river flowing on Mars, would have been an ideal landscape for ancient microbial life, had such life existed. But a treacherous dune field, which the rover cannot cross, lies between Perseverance and the delta. Researchers are discussing whether to drive the rover clockwise or anticlockwise around the dune field; the latter would make for a shorter trip, but the former would take Perseverance past a greater variety of interesting rocks.
None of this is likely to happen, however, until June at the earliest. First, Perseverance must drive to a suitable spot for it to test Ingenuity, its helicopter. This place will probably be a rock-strewn area not too far from the rover’s current location. There, the rover will lower Ingenuity from its belly, drive off a safe distance and shoot a video as the helicopter takes to the Martian skies. “We’re looking forward to those historic, aviation-first movies,” said Jim Bell, a planetary scientist at Arizona State University in Tempe who leads one of the rover’s camera teams. The helicopter test comes first because Ingenuity will fly with the rover as it drives, helping Perseverance to navigate its way across the landscape.
Until that first flight test, which is expected no earlier than the first week in April, team scientists will continue to explore the rocks around the landing site. Immediately surrounding the rover are lighter-coloured rocks peeking out from dark soil. Perseverance has used a laser-based instrument to determine that several of these rocks, including two that team scientists named Máaz and Yeehgo, are chemically similar to basaltic rocks on Earth, which form from molten rock. The instrument zaps rocks with a laser to vaporize small portions and study their chemical make-up. Through this analysis, the scientists have seen that Yeehgo shows signs of having water locked up in its minerals, said Roger Wiens, a geochemist at Los Alamos National Laboratory in New Mexico who is head of the laser-instrument team. These discoveries fit with what scientists had expected from Jezero — that it might have volcanic rocks on the crater floor, which could have interacted with water over time.