On April 6, the incredibly sensitive seismic detector the lander brought with it captured a tiny movement from the
interior of the planet. The tentatively confirmed signal may have company from similar tremors measured on March 14, April 10 and April 11, but scientists aren't positive yet what triggered those incidents and can't confirm their shakes reflect interior activity.
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.
Although the scientists are excited by the detection, it won't help them tackle the ultimate goal of the InSight mission, which is to analyze the
interior structure of Mars. This particular quake was not strong enough to produce the data they need for that analysis.