A Marsquake detected by NASA's InSight lander in May this year was at least five times larger than the next largest seismic event recorded on the planet.
The quake occurred on May 4 and registered at a magnitude of 4.7 — five times more powerful than the InSight lander's previous largest quake on Mars back in August 2021, which was recorded at a magnitude around 4.2. Another indication of the scale of the event is that InSight continued detecting waves from the record-breaking quake for around 10 hours, while the after-effects of all previous Marsquakes had subsided within an hour.
"The energy released by this single marsquake is equivalent to the cumulative energy from all other Marsquakes we've seen so far," John Clinton, a seismologist at the Swiss Federal Institute of Technology in Zürich and co-author of the study, said in a statement from the American Geophysical Union, which published the research. "Although the event was over 2,000 kilometers (1,200 miles) distant, the waves recorded at InSight were so large they almost saturated our seismometer."
InSight launched in May 2018 and landed on Mars in late November that year. Since then, it has been using its seismometer to detect activity on the Red Planet, which is seismically much more placid than Earth. Recording Marsquakes is providing new information about Mars, with the movements of waves through the planet revealing new insights into its crust, mantle and core.
"For the first time we were able to identify surface waves, moving along the crust and upper mantle, that have traveled around the planet multiple times," Clinton said.
The seismic event in May was also unusual because its epicenter wasn't near known nodes of activity. It also displayed characteristics of both types of marsquakes so far discerned: high-frequency waves with rapid but shorter vibrations and low-frequency waves with larger amplitude.
The marsquake occurred on Sol 1222 of InSight's mission (a sol is one day on Mars and lasts about 40 minutes longer than a day on Earth). NASA has said that InSight only has weeks left to live before its ceases functioning due to a build up of dust on its energy-generating solar arrays. The lander has, however, already far outlived its primary mission lifetime of two Earth years.
The research is described in a paper published Wednesday (Dec. 14) in the journal Geophysical Research Letters.