For the first time, NASA’s Mars InSight lander has successfully recorded and measured what seems to be a tremor on the red planet. Scientists say the source for this “Marsquake” could either be movement in a crack inside the planet or the shaking from a meteorite impact.

On April 6, the Mars InSight lander’s seismometer recorded a short series of howls, grumbles, and pings. One of those sounds — a grumble — is probably a Marsquake, representing the first recorded sound from the interior of the Red Planet.

The recording, released by NASA April 23, lasts about 40 seconds. It begins with the faint, eerie howling of the Martian wind, followed by the low rumble of the possible Marsquake. A large ping toward the end is the spacecraft’s robotic arm moving.

NASA states that this is the first recorded seismic activity that appears to have come from inside the planet rather than being caused by any outside forces such as wind. Scientists assert, Mars is not nearly as geologically active as Earth and, like our moon, lacks tectonic plates.

Quakes occur on our planet due to the motion of those tectonic plates. Though Mars doesn’t have any, a continuous process of cooling and contraction creates stress that builds over time, thus leading to a break in the crust which can lead to a Marsquake.

Scientists hope that InSight’s data will ultimately reveal the planet’s internal structure, including the size and density of its crust, mantle, and core, how heat flows through the planet, and even whether there might be water in the interior or not.