The InSight Lander touched down on the surface of Mars almost four years ago with a mission to learn what is happening in the planet’s interior. This stationary lander was sent to check the “vital signs” of Mars, including pulse (seismicity) and temperature (heat flow). One of InSight’s many tasks is detecting marsquakes and recording meteoroid impacts. A recently published paper by Liliya Posiolova from Malin Space Science Systems and colleagues describes a marsquake detected on December 24, 2021. Results of this study show that the magnitude 4.0 marsquake was caused by a meteoroid impact. The meteoroid was approximately 5 to 12 meters long, left a crater 150 meters in diameter and 21 meters deep, and sprayed ejecta almost 37 kilometers. The meteoroid collided with the surface 3,500 kilometers away from the lander. The seismic data collected by InSight will help scientists determine the structure and composition of the red planet’s crust and mantle.
While it is impressive in and of itself that InSight detected one of the largest meteoroid strikes on the planet since NASA started studying Mars, the ejecta from the impact led to another exciting discovery. Images from the HiRISE camera aboard the Mars Reconnaissance Orbiter revealed that boulder-sized ice chunks were part of the ejecta thrown out from the impact crater. This is the closest to the equator of Mars that ice has ever been detected. Studying this ice will help scientists better understand Mars’ past, including its climate history and how and when the ice was deposited. This ice may also be useful as possible human landing sites are considered, given that the ice may be used for drinking water, watering crops, and rocket propellant. READ MORE