On May 4, 2022, NASA's InSight lander detected the largest quake yet recorded on Mars, one with a 4.7 magnitude — fairly modest by Earth standards but strong for our planetary neighbor.

Given that Mars lacks the geological process called plate tectonics that generates earthquakes on our planet, scientists suspected a meteorite impact had caused this marsquake. But a search for an impact crater came up empty, leading scientists to conclude that this quake was caused by tectonic activity — rumbling in the planet's interior — and giving them a deeper understanding about what makes Mars shake, rattle and roll.

"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."