The Perseverance rover is bristling with scientific instruments and cameras, but it can only do so much on the surface of Mars. Thus, NASA plans to transport the rover’s samples back to Earth in the coming years, but first, Perseverance has to add bits of Mars to its collection. NASA reports Perseverance has just grabbed its first sample of regolith, the ultra-fine mixture of broken rocks and dust that covers the Martian landscape.
NASA says that Perseverance collected two regolith samples, one on Dec. 2 and another on Dec. 6. The samples came from a “pile of wind-blown sand and dust similar to but smaller than a dune.” Most of the rover’s sample tubes will be filled with rock cores, but NASA created a special drill bit for the mission to collect regolith. The closest analog to Martian soil is probably sand, so you might wonder why the rover is using a drill bit to collect it instead of, say, a shovel. Since the sample tubes integrate with the drill, it’s simpler to just use that same mechanism to get regolith into a tube. These tubes are ultra-clean and sealed up tight to ensure the samples are not contaminated when they return to Earth.
Engineers on Earth designed the special drill bit after testing with artificial Martian soil, known as Mojave Mars Simulant. It’s composed of volcanic rock that has been pulverized to various particle sizes, from small pebbles to microscopic dust. Although, no one has ever analyzed Martian regolith in a laboratory. Getting samples back to Earth is the first step in better understanding the surface of a planet that humans may one day visit.
NASA will search for evidence of ancient alien life in the regolith, but fully characterizing the composition and behavior of the regolith is also important. For one, future missions could benefit from more accurate Mars soil simulants. The InSight lander’s burrowing heat probe was supposed to take the planet’s temperature, but NASA didn’t realize how quickly Martian fines would slip down in front of the probe as it tried to hammer itself deeper. NASA eventually gave up on that part of the mission. Perhaps more realistic simulated soil would have helped catch the issue.
A return to the current goal of NASA’s crewed spaceflight program, but Mars is on the agenda for the 2030s. Knowing how the regolith interacts with spacesuits and habitats is vital to a successful mission, and the samples just collected by Perseverance could help. The Mars Sample Return mission, a partnership between NASA and the ESA, is on the schedule for the late 2020s. The samples could be back on Earth as soon as 2033.