NASA’s InSight lander has detected the first seismic and acoustic waves generated by meteorite impacts on Mars and was even able to locate impact craters.
It is a unique observation method even on Earth, where few meteorite impacts have been recorded with systems like InSight. Those responsible for this project, who have published an article with the findings in Nature Geosciencepoint out that although seismic and acoustic waves from meteorites exploding into Earth’s atmosphere have been observed many times, “a hypervelocity impact with the ground was only recorded once.”
The first of the confirmed meteorites entered the atmosphere of Mars on September 5, 2021, and exploded into three fragments, each of which left a crater. The Mars Reconnaissance Orbiter then flew over the estimated impact site to confirm the location.
“After three years of InSight waiting to detect an impact, those craters looked beautiful,” Ingrid Daubar of Brown University, a co-author of the paper and a Mars impact specialist, said in a statement.
After analyzing earlier data, the scientists confirmed that there had been three other hits on May 27, 2020, February 18, 2021 and August 31, 2021.
Researchers wonder why they haven’t detected more meteorite impacts on Mars. The Red Planet is adjacent to the Solar System’s main asteroid belt, which provides an ample supply of space rocks to mark the planet’s surface. Because Mars’ atmosphere is only 1% thicker than Earth’s, more meteorites pass through it without disintegrating.
InSight’s seismometer has detected more than 1,300 earthquakes. Provided by France’s space agency, the Center National d’Études Spatiales, the instrument is so sensitive that can detect seismic waves thousands of kilometers away. But the September 5, 2021 event marks the first time an impact has been confirmed. as the cause of such waves.
The InSight team suspects that other impacts may have been obscured by wind noise or seasonal changes in the atmosphere. But now that it’s been discovered the distinctive seismic signature of an impact on MarsScientists hope to find more hiding within nearly four years of InSight data.