On December 19th, Mars InSight lander's ground team moved the vehicle's arm as far as it could reach and planted its seismometer 5.367 feet away. Seeing as the lander's main goal is to gather data so we can learn more about the red planet's interior, the team considers that seismometer its most important instrument. The mission's Principal Investigator, Bruce Banerdt, said seismometer deployment is as significant as landing InSight on Mars. "We need it in order to complete about three-quarters of our science objectives," he explained.
InSight took photos of its landing site -- it snuck in a selfie, too -- as soon as it could in an effort to help scientists find the perfect position for the seismometer and its other instruments. Since its landing site turned out better than expected, with "near-absence of rocks, hills and holes," NASA was quickly able to decide on a location.
The InSight will work on making sure the instrument perfectly level these next few days, since the ground is tilted by a couple of degrees. And in the next few weeks, they'll make sure the data it returns is as clear as possible. The scientists need to ensure the seismometer is perfectly placed, since they're relying on it to monitor seismic waves passing through layers of the planet whenever there's a marsquake. Philippe Lognonné, the seismometer team leader, likens the placement to holding a phone up to your ear.
The team plans to follow this up by planting the InSight's heat probe onto the Martian surface late January. Any data both instruments gather will give NASA researchers what they need to deduce the depth and composition of the planet's layers, along with other information that can help them figure out how similar planets form.