NASA’s beleaguered InSight lander on Mars detected a magnitude 5 “marsquake,” the largest the spacecraft has felt so far since landing on the planet in November 2018. It’s a significant moment that comes during a difficult time for InSight, as the spacecraft’s solar power panels continue to collect dust that will eventually end the rover’s life on Mars.
InSight’s mission on the Red Planet has been to probe the interior of Mars, primarily by detecting tremors on the surface. Unlike earthquakes here on Earth, which are usually caused by shifting tectonic plates, “marsquakes” are thought to be caused by Mars cooling over time, making that the planet’s crust becomes more brittle and cracks. Equipped with an extremely sensitive seismometer built by France’s space agency, InSight has detected more than 1,313 earthquakes since it landed three and a half years ago, according to NASA.
The initial earthquakes that InSight felt were of relatively low magnitude. So far, the largest earthquake the spacecraft had detected was magnitude 4.2. This latest 5-point quake, detected on May 4, is still pretty weak compared to the ones we sometimes experience on Earth, but NASA says it’s close to the strongest kind of quake scientists expect to see on Mars. Now the InSight team will dive into the earthquake data to learn more about its origin and scope. “Since we installed our seismometer in December 2018, we’ve been waiting for ‘the big one,'” Bruce Banerdt, InSight principal investigator at NASA, said in a statement. “This earthquake is sure to provide a view of the planet like no other.”
It’s a victory for InSight, which has struggled since landing. The mission’s first big problem arose when the spacecraft attempted to deploy one of its main instruments shortly after landing: a heat probe called a “mole.” Designed to burrow below the Martian surface to measure the planet’s internal temperature, the mole was never able to acquire the proper friction it needed to burrow deep into the ground. Intending to reach a depth of up to 16 feet, the mole barely made it below the surface. Finally, after two years of trying, NASA decided to end the mole excavation attempts to focus on the overall InSight mission.
But InSight has also been going through a tough time lately. In January, a particularly thick Martian dust storm prevented enough sunlight from reaching InSight’s solar panels, reducing the spacecraft’s power supply. In response, InSight entered safe mode, a type of operating procedure in which the spacecraft stops performing all but the most essential tasks for survival. Eventually InSight came out of safe mode and started producing full power again. But dust continues to collect on InSight’s solar panels, and the rover doesn’t have a way to meaningfully clean its hardware (although NASA has tried some unconventional techniques). Since there haven’t been particularly strong winds to blow away the dust, InSight will eventually stop producing enough power to keep running, which is expected to happen later this year.
Despite all this, InSight has achieved its main objectives as expected. Its primary mission ended in December 2020, and the lander is currently on its extended mission, which lasts until December 2022. As of now, there is still time to detect more marsquakes until the power runs out.