Meteorite shock waves help scientists locate new craters on Mars | Mars

Researchers have identified new pits on Mars Using shock waves caused by clumps of space rocks as they rip the sky and collide with the Earth.

The new scars on the planet’s face are the first archaeological craters ever traced from the roar and crash of the surging meteors bombarding another planet. The findings will help scientists build a more accurate picture of how often Mars is hit by the solar system’s rocky detritus and improve their understanding of the deep inner structure of our planetary neighbor.

Professor Rafael Garcia, planetary seismologist at the Higher Institute of Aeronautics and . said: space at the University of Toulouse.

To see if they could find craters from incoming meteorites on Mars, researchers examined seismic waves recorded by NASA’s InSight lander between May 2020 and September 2021. landed In the barren expanse of Elysium Planitia in November 2018 on a mission to investigate the planet’s structure, crust, and impact activity.

Scientists expected InSight to detect between one and 100 impacts every five Earth years using the sensitive seismometer deployed on the surface of Mars. The seismic data recorded by the probe included four collision events that the researchers explored in detail.

By figuring out how quickly sound and seismic waves travel through the Martian air and rock, the team estimated how far from Insight the various meteorites hit the surface. Then they set the direction.

A loud bang on impact sends sound waves racing across the surface in all directions. This ground distorts imperceptibly, but the Insight data was so sensitive that the team chose the direction of the impact from the slight tilt of the seismometer during the sonic wave sweep.

The analysis allowed scientists to predict roughly where the incoming meteorites would crash to the surface. To check for signs of new craters, they turned to images taken by NASA’s Mars Reconnaissance Orbiter. Before and after images from this probe revealed new black spots on Earth – newly formed craters near the expected impact sites.

A single meteorite reached Mars on September 5, 2021 and released three intense shock waves. The first came when it collided with the atmosphere of Mars at a speed of 10 kilometers per second, causing a shock wave along its path. The space rock then exploded at an altitude of 13-16 km, producing multiple fragments. Then it fell into the ground, creating a group of new craters several meters wide.

The data is of great value to planetary scientists who study the structure of Mars’ crust because the source of seismic waves can be identified in the crater. But impact craters are also used as cosmic clocks, with older surfaces on planets and moons pierced by more craters than younger ones.

“If people want to know if the surface is older or younger, it is very important to know the impact rate, but we are not there yet,” Garcia said. the details Published in Nature Geoscience.