What Caused a Record-Breaking Quake on Mars

InSight burying a seismometer’s cable. Photo Credit: NASA

Since NASA’s InSight lander touched down on Mars’ equator, the Elysium Planitia, in November 2018, it has returned information on Mars (marsquakes) and some possible models for the core of the planet and its orbit. While the Martian regolith and hard soil made drilling nearly impossible, InSight has been able to provide data on numerous seismic events that have granted NASA with extensive data regarding the nature of the planet’s seismology and geological traits.

On the robot’s first Martian day, scientists used Frank Zappa’s “Dog Breath, In The Year Of The Plague” to awaken it, marking the first time a wakeup song was used for a spacecraft on another planet.

Over 1,300 seismic events were recorded from 2018 to the project’s dissolution in 2022. The largest cluster of high-quality events from the $814 Mn mission came from a region that shows key evidence of geologically recent volcanism, within the last two million years. From the middle of 2021 to late 2022, the instrument detected six of the mission’s largest events. The biggest, in May of 2022, had an estimated magnitude of 5 which lasted six hours.

Mars’ lack of tectonic activity had led scientists to believe that a meteorite caused the quake in question. Being that an impact crater wasn’t found, a new outlook on the rumbling of the planet has become operative. The major seismic event that took place well over a year ago indicates that S1222a was caused by the release of huge tectonic forces from within the Martian interior.

After 1,500 days on Mars, mission managers declared the program’s end on December 21st, 2022, after the lander failed to respond to two messages from mission control at NASA’s Jet Propulsion Laboratory in Pasadena, California.

In a recent study, a team from the University of Oxford worked with the European Space Agency, Chinese National Space Agency, the Indian Space Research Organisation, and the United Arab Emirates Space Agency to scour more than 55 million square miles on Mars.

“We concluded that the largest marsquake seen by InSight was tectonic, not an impact. This is important as it shows the faults on Mars can host hefty marsquakes,” said planetary scientist Ben Fernando of the University of Oxford in England, lead author of the research published this week in the journal Geophysical Research Letters. “We really thought that this event might be an impact.”

“This represents a significant step forward in our understanding of Martian seismic activity and takes us one step closer to better unraveling the planet’s tectonic processes,” added Imperial College London planetary scientist and study co-author Constantinos Charalambous, co-chair of InSight’s Geology Working Group.