Seismic Data Reveals Frequent Meteorite Impacts Shaking Mars

Recent seismic data reveals that Mars is frequently struck by meteorites, causing significant quakes on the planet. By analyzing information from NASA’s InSight lander, an international team of researchers identified six seismic events linked to meteorite impacts, unveiling a new category of quakes known as VF (very high frequency) events.

Meteorites impact Mars daily. The SEIS seismometer on the InSight lander detected six seismic events that matched the atmospheric acoustic signals generated by meteorites. These VF events occur much faster than typical tectonic quakes, often in fractions of a second, providing key data on the occurrence of meteorite-induced quakes on Mars. This marks the first time seismic data has been used to estimate the frequency of impact craters on the planet.

“While we cannot entirely rule out non-impact origins for each VF event, our findings strongly suggest that the VF class is caused by meteorite impacts,” the researchers stated in a study published in Nature.

Seismic Shift

Traditionally, scientists estimated meteorite impact rates on Mars by comparing crater frequencies with lunar crater data. However, this method was flawed as Mars, being more massive and closer to the asteroid belt, experiences more frequent impacts. Additionally, Martian craters are often obscured by dust, complicating identification efforts.

After landing in the Elysium Planitia region, InSight's SEIS instrument detected seismic waves from meteorite impacts, similar to tectonic marsquakes. A notable quake detected by SEIS corresponded with a 150-meter-wide crater. Subsequent analysis identified five more quakes linked to the distinctive acoustic signals of meteorite impacts.

A Huge Impact

The VF marsquakes, caused by meteorites traveling over 3,000 meters per second, are faster than any other type of marsquake, earning them their classification. Imaging from the Mars Reconnaissance Orbiter’s (MRO) Context Camera (CTX) confirmed the presence of new craters at these event locations.

Additional seismic events detected by SEIS, likely caused by smaller meteorites, have not been linked to visible craters due to their size. By estimating crater diameters based on seismic wave travel times and VF quake magnitudes, researchers concluded that around 280 to 360 VF quakes occur annually on Mars.

“The evidence strongly supports that VF marsquakes are consistent with impacts,” the researchers noted. “Considering all VF events as meteoroid impacts provides valuable insights.”

This discovery has expanded the estimated number of impact craters on Mars, many of which were previously undetectable from space. Understanding the rate of meteorite impacts helps determine the age of planetary surfaces and offers vital information for protecting future spacecraft and astronauts from potential hazards.

While Earth’s thick atmosphere protects us from most meteorites, Mars’s thin atmosphere allows more to reach the surface, posing a greater risk.