Biggest marsquake on record marks InSight's swansong
NASA’s InSight lander has detected the strongest and longest quake on Mars so far. The event was five times more powerful than any previous marsquake, unleashing as much energy as all others combined, and with the lander failing the record is unlikely to topple.
The record-breaking quake, designated S1222a, occurred on May 4, 2022, and registered a magnitude of 4.7. That’s not huge as far as regular old earthquakes go, but for the far less seismically active Mars, that’s pretty powerful. In fact, it’s five times stronger than the previous record-holder – a magnitude 4.2 quake detected in August 2021.
“The energy released by this single marsquake is equivalent to the cumulative energy from all other marsquakes we've seen so far, and although the event was over 2,000 km (1,200 miles) distant, the waves recorded at InSight were so large they almost saturated our seismometer,” said John Clinton, co-author of a study describing the event.
This powerful quake had a few other notable features, too. S1222a lasted at least four hours, more than twice the duration of the previous longest, and was the first on record to send seismic waves rippling all the way around the entire surface of Mars. And while most marsquakes are found to send off either high- or low-frequency surface waves, this marked the first time both types were detected at once.
Other waves travel deeper underground, and analyzing the speed at which these move can reveal the composition of the planet. When scientists studied those deeper waves from S1222a, they found that the Martian crust seemed to be made up of layers of different materials.
“This wave speed information is related to deformations inside the crust,” said Caroline Beghein, corresponding author of another study. “Alternating volcanic rocks and sedimentary layers, which were deposited long ago, or a very large impact, such as a meteoroid, most likely account for the seismic wave measurements we observed.”
S1222a will probably remain the most powerful marsquake InSight ever detects – the lander is due to run out of power essentially any day now, after its solar panels were caked in dust from several storms.