NASA’s ailing Mars lander feels shockwaves from ice-blasting impact
Christmas came one day early for a lone geologist stationed on the Red Planet.
NASA’s InSight mission touched down on Mars in November 2018 to peer inside the planet, mapping its layers and faultlines. And on Dec. 24, 2021, the lander made a remarkable detection, catching seismic waves from a sizeable meteoroid impact. Photos taken from orbit made the signal even more intriguing, because scientists tied the seismic detection to the sight of a large, fresh crater.
“It was immediately clear that this is the biggest new crater we’ve ever seen,” Ingrid Daubar, InSight impact science lead and a planetary scientist at Brown University, said during a news conference held on Thursday (Oct. 27).
“We thought a crater this size might form somewhere on the planet once every few decades, maybe once a generation,” Daubar said. “So it was very exciting to be able to witness this event, and to be lucky enough that it happened while InSight was recording seismic data — that was a real scientific gift.”
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In September, InSight scientists announced four detections of meteorite impacts, each also tied to a fresh crater, that were made in 2020 and earlier in 2021.
But these were small impacts: None produced seismic signals stronger than a magnitude 2 quake. InSight team members had deemed it unlikely that they’d see signals from more powerful strikes, so the lander’s Christmas Eve data were a bolt from the blue. Those observations pointed to an impact that clocked in at magnitude 4 and produced a crater more than 430 feet (130 meters) wide. (InSight also observed a similar impact in September 2021, which the mission team described in the scientific papers announcing these findings.)
But even while InSight scientists were digging into what the Christmas Eve impact might mean, scientists with NASA’s Mars Reconnaissance Orbiter (MRO), which has been studying the Red Planet since 2006, made a different discovery when they spotted a fresh, large impact crater.
“When we first saw this image, we were extremely excited,” Liliya Posiolova, orbital science operations lead for MRO at Malin Space Science Systems in California, said during Thursday’s briefing. “This was nothing like we’ve seen before.”
Posiolova and her colleagues first spotted the fresh crater in data gathered by MRO’s Context Camera. The crater and the rays of debris circling the impact site filled an entire frame, 19 miles (30 kilometers) wide. “We needed to take two more images on the sides to capture the entire perturbance area.”
Daubar said that the crater itself stretches about 500 feet (150 m), which she compared to two city blocks and noted was 10 times the size of a typical new crater on Mars. Posiolova said that fresh impact craters usually look like mere smudges in MRO’s data.
Working backward from the size of the crater, scientists estimated that the asteroid that slammed into the Red Planet was between 16 feet (5 m) and 40 feet (12 m) wide before it met its fate. Had it struck…
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