Mars isn’t static inside: The planet is shaken by marsquakes which are measured by NASA’s InSight lander in order to investigate the interior of the planet. This month, the lander detected one of its biggest ever marsquakes, which hit a magnitude of 4.2 and lasted for nearly ninety minutes on September 18.
This is part of a shaky season on Mars, with the lander detecting two other quakes within the last month — another of magnitude 4.2 and one of 4.1, both of which occurred on August 25. “For comparison, a magnitude 4.2 quake has five times the energy of the mission’s previous record holder, a magnitude 3.7 quake detected in 2019,” NASA writes.
NASA scientists say they’re still learning about the September quake, but they already have some data on the August quakes. They pinpointed the location of the larger quake to a distance of 5,280 miles away from the lander, making it the most distant detected so far. That means that, unlike most previously detected quakes, this one didn’t originate in the Cerberus Fossae region. It may have originated from the Valles Marineris canyon which stretches around the planet’s equator.
The other August quake was of a different type, being fast and high-frequency as opposed to slow and low-frequency, and was also close at a distance of 575 miles. This is fortuitous as researchers can use different types of quakes to learn more about the interior structure of Mars.
And the fact that InSight is operating at all is fortuitous as well. As Mars has an elliptical orbit, it recently traveled further from the sun than average, which means less solar power was available. And the dust which covers everything on the planet was causing problems too by covering the lander’s solar panels.
The mission might have been scuppered altogether by the lander running out of power, but the team were able to keep it going by cleaning the solar panels using more dust and putting the lander into hibernation for the winter.
“If we hadn’t acted quickly earlier this year, we might have missed out on some great science,” said InSight’s principal investigator, Bruce Banerdt of NASA’s Jet Propulsion Laboratory in Southern California, which leads the mission. “Even after more than two years, Mars seems to have given us something new with these two quakes, which have unique characteristics.”