Marsquake!

Scientists just felt the Red Planet move under their feet — robotically from millions of miles away, on the stark surface of Mars. On April 6, NASA's InSight lander sensed its first confirmed marsquake, a phenomenon scientists suspected, but couldn't confirm, occurred on the neighboring planet. Measuring the Martian equivalent of earthquakes, seismic waves traveling through the interior of the planet, was among the lander's key science goals. Scientists never thought marsquakes would be as frequent as their terrestrial equivalents are because Mars doesn't sport the tectonic plates whose jostling interactions prompt many quakes here on Earth. But they suspected that the stress caused by the slow cooling of the body could trigger sporadic quakes as energy rippled through the planet's interior.

"We've been waiting months for our first marsquake," Philippe Lognonné, the principal investigator for the seismometer instrument, said in a statement released by the French space agency, which runs the instrument with the national research center. "It's so exciting to finally have proof that Mars is still seismically active." The scientists behind the seismometer always knew they were facing a tricky challenge. The instrument had to be carefully designed if it was to succeed in picking up incredibly precise signals. It also needed protection from the wind, which is why the instrument itself is covered by a white dome, a shield that helps the instrument focus only on the interior of the planet. And because the scientists could only place a single detector, they needed to find a way to replicate the triangulation process that the seismic network on Earth permits naturally. The April 6 signal is the reward they've earned for that intricate design process.



Credits:
https://www.space.com/insight-mars-lander-first-marsquake.html