NASA is sending a piece of rock from Mars back to the Red Planet on board the Mars 2020 rover mission. The Martian meteorite will be used as a calibrating target in one of the rover instruments that will be mounted on the rover’s robotic arm.
The rover is equipped with a laser that can illuminate features as thin as a human hair and that requires exquisite calibration. To achieve that the lasers have a variety of target materials that can help tweak the settings of the instruments. A fragment of a Martian meteorite will now be part of the targeting pallet.
"We're studying things on such a fine scale that slight misalignments, caused by changes in temperature or even the rover settling into sand, can require us to correct our aim," Luther Beegle, from NASA’s Jet Propulsion Laboratory, said in a statement. "By studying how the instrument sees a fixed target, we can understand how it will see a piece of the Martian surface."
Beegle is the principal investigator of one of the Mars 2020 instruments, which has the phenomenal backronym of SHERLOC – Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals. The instrument will use ultraviolet light to shine over the Martian rock samples and if certain carbon compounds are present the samples will glow. SHERLOC will also image the rocks it studies to help planetary scientists understand where the interesting chemicals came from.
"This kind of science requires texture and organic chemicals – two things that our target meteorite will provide," added Rohit Bhartia of JPL, SHERLOC's deputy principal investigator.
Using a Martian meteorite wasn’t a whimsical decision. These objects are rare with only about 200 known. The team needed a strong meteorite that could survive launch and landing. They found a great one in the collection of London’s Natural History Museum, using a fragment from SaU008, which was found in Oman in 1999
"Every year, we provide hundreds of meteorite specimens to scientists all over the world for study," Caroline Smith, principal curator of meteorites at the Natural History Museum, said. "This is a first for us: sending one of our samples back home for the benefit of science."
This will be the first Martian meteorite to be taken back to the surface but it’s not the first one to be Mars-adjacent. NASA’s Mars Global Surveyor, a spacecraft that began orbiting the Red Planet in 1997, had a piece of the Zagami meteorite inside.