National Geographic:

Now that its solar panels are set up, it’s time for InSight to get to work. Over the course of one Martian year (or at least two Earth years), it will do something a bit different from most other Mars missions, which have focused on the planet’s flashy rift valleys, mammoth volcanoes, or signs of ancient running water on the surface.

Instead, this mission aims to get at the heart of Mars, to measure the size of the planet’s core and other interior layers. To do this, it will rely on marsquakes—or tremors that are often produced by the same tectonic activity that crafts those beautiful mountains and valleys.

One of InSight’s primary goals is to figure out how seismically active Mars is, says Renee Weber of NASA’s Marshall Space Flight Center.

I was lucky enough to watch the landing live with a couple of 12-year-olds. I was as excited about it as they were.