NASA’s InSight Mars lander has detected seismic waves from four space rocks that crashed on Mars in 2020 and 2021.
September 19, 2022
NASA’s InSight Mars lander has detected seismic waves from four space rocks that crashed on Mars in 2020 and 2021.
Not only do these represent the first impacts detected by the spacecraft’s seismometer since InSight touched down on Mars in 2018, but it also marks the first time seismic and acoustic waves from an impact have been detected on the red planet —a development providing scientists a new way to study Mars’s crust, mantle and core.
A new study published in Nature Geoscience—on which Brown University Assistant Professor (research) of Earth, Environmental and Planetary Sciences Ingrid Daubar is a co-author—details the impacts, which ranged between 53 and 180 miles from InSight’s location, a region of Mars called Elysium Planitia.
“It was super exciting,” Daubar recalled of the impacts. “My favorite images are the ones of the craters themselves. After three years of waiting for an impact, those craters looked beautiful.”
Of the four confirmed meteoroids, which is the term used for space rocks before they hit the ground, the first one the team found made the most dramatic entrance: It entered Mars’ atmosphere on Sept. 5, 2021, exploding into at least three shards that each left craters behind.
When NASA’s Mars Reconnaissance Orbiter flew over the estimated impact site to confirm the location, it used its black-and-white context camera to reveal three darkened spots on the surface. After locating these spots, the orbiter’s team used the High-Resolution Imaging Science Experiment camera to get a color close-up of the craters. There is also audio of the impacts available.
After combing through earlier data, three other impacts were confirmed as occurring on May 27, 2020; Feb. 18, 2021; and Aug. 31, 2021.
“Having a really precise location for the source of the impacts calibrates all other data for the mission,” Daubar said. “This validates the estimates we’ve made and will allow us to do this more precisely… It also tells us a lot about the impact process itself and the seismic results. We’ve never actually seen this before.”
Researchers have puzzled over why they haven’t detected more meteoroid impacts on Mars. The red planet is next to the solar system’s main asteroid belt, which provides an ample supply of space rocks to scar the planet’s surface. Because Mars’ atmosphere is just 1% as thick as Earth’s, more meteoroids pass through it without disintegrating.
Moreover, InSight’s seismometer has detected more than 1,300 “marsquakes.
