Scientists Detect the Biggest Extraterrestrial Earthquake Ever

A robot on Mars has detected the biggest earthquake ever felt on another planet, a Martian tremor that reached a magnitude of 5 on the Richter scale, according to a statement issued on Monday from NASA’s Jet Propulsion Laboratory (JPL). The record-breaking “marsquake” not only demonstrates geological activity on Mars, but also opens a window into the mysterious interior of the red planet.

The quake was captured by NASA’s InSight mission, a lander that touched down on Mars in November 2018. InSight is equipped with a sensitive component called the Seismic Experiment for Interior Structure (SEIS), which is the first seismometer ever deployed on an extraterrestrial world. 

Designed and built by France’s National Center for Space Studies, which is the nation’s governmental space agency, SEIS has recorded more than 1,300 marsquakes since it began operating some three years ago. 

However, none has come close to matching the intensity of the magnitude 5 “monster quake,” as JPL described it, that shook Mars last Wednesday, May 4. On Earth, this magnitude would be classified as a common medium-sized event, somewhat similar to a quake that struck Namibia last month, but on Mars, this strength is much more rare. The previous record-holder, which occurred in August 2021, reached a magnitude of 4.2, making it just a sixth of the strength of the recent quake on the logarithmic Richter scale.

As seismic waves pass through the Martian crust, mantle, and core, they bounce off, or pass through, various interior structures. As a result of these encounters, rumbles detected by InSight can be mined for valuable information about the size, composition, and distribution of features inside the planet. This data can, in turn, help to unravel the story of Mars’ formation and evolution, and by extension, shed light on other rocky planets such as Earth.

During the first two years of the mission, scientists were perplexed by the lack of marsquakes that topped magnitude 4. Now, the lander has observed its biggest marsquake yet, a milestone that will reveal new insights about the underground layers of Mars. 

“Since we set our seismometer down in December 2018, we’ve been waiting for ‘the big one,’” said Bruce Banerdt, InSight’s principal investigator at JPL, in a statement. “This quake is sure to provide a view into the planet like no other. Scientists will be analyzing this data to learn new things about Mars for years to come.”