The surface of Mars is pretty quiet. It doesn’t constantly move and shake, as Earth’s does. Even so, it does jiggle a bit. And scientists are hoping to use those jiggles to learn more about what’s happening below the surface.
They heard their first confirmed “marsquake” back in April. It was detected by a seismometer deployed by InSight, which is probing Mars’s interior. The craft landed last November. It then used its robotic arm to place the seismometer on the surface in December.
The seismometer consists of three sensors that touch the surface. They’re housed inside a small dome that protects them from the wind and from changing temperatures. Yet the seismometer still “hears” the wind. In fact, it was recording the wind on April 6th when it heard a deeper rumble.
According to mission scientists, that was the first confirmed marsquake ever heard. One of the Viking landers of the 1970s recorded a possible quake, but it also could have been a strong gust of wind. And InSight heard a few weaker signals earlier in the year, but it’s not certain if they were caused by quakes, either.
The number and intensity of marsquakes can tell scientists how “active” the planet is — whether it has moving fault lines, for example. And as the sound waves from the quakes bounce around inside Mars, they can reveal details about how the planet is put together — all from a few “jiggles” on the Red Planet.
Tomorrow: harvesting moonlight.