When a potent 4.7 magnitude earthquake rattled Mars in May of 2022, it was big. It wouldn’t have shaken dishes on Earth, but it would have made a building’s wooden frames creak, at the very least. It was the largest seismic event recorded on the Red Planet and lasted six hours.
The scientists overseeing NASA’s InSight mission have finally unveiled the quake’s source. They’ve been working on it for months and are now ready to share their findings with the world.
InSight landed on Mars in November 2018 to listen keenly for vibrations from the planet’s crust and interior. It spotted over 1,300 earthquakes, but most were only a few seconds long. Then, on May 4, 2022, the probe picked up a far longer rumble than usual. It lasted six hours and sent seismic surface waves around the planet’s perimeter. That was unusual, as Mars doesn’t have plate tectonics and is generally not seismically active.
So what was going on? The international researchers led by planetary physicist Benjamin Fernando at the University of Oxford set out to find out. They reviewed data from InSight’s seismometer and matched it with images taken by the Mars Reconnaissance Orbiter. They looked for a fresh crater, a dust cloud, or other evidence of a meteorite impact that could explain the quake.
Searching through the vast amount of data InSight collected took a while. The team had to discard some possibilities. They couldn’t rule out the meteorite strike, but it was hard to explain the quake’s duration and that the shaking didn’t trigger a landslide. That’s when they began to suspect something else was happening.
They also realized that the quake wasn’t located in the region of the planet known as Cerberus Fossae, where they expected to find signs of tectonic activity. So they consulted with the European Space Agency, the Chinese National Space Administration, the Indian Space Research Organisation, and the United Arab Emirates space agencies for help. Eventually, they discovered that the quake resulted from a giant stress release within the Martian crust.
That’s important because it suggests Mars is much more seismically active than thought. While the planet doesn’t have plate tectonics at the moment, it does have a lot of tension built up over billions of years as different parts of the planet cool and shrink at their rates. The 4.8 magnitude quake resulted from that tension suddenly relaxing, sending ripples outward from the point of origin. Read more about the massive quake on Mashable. Want more science and tech news like this? Sign up for our Light Speed newsletter today!