NASA talks about three things learned from the Mars InSight mission
NASA's Mars InSight spacecraft landed on the surface of the Red Planet on November 26, 2018. The goal of the mission is to study the interior of Mars. A bit more than two years later, or a bit more than one Martian year, the lander and its science instruments have detected more than 480 quakes.NASA's spacecraft also collected the most comprehensive weather data of any mission ever sent to Mars. While the probe has struggled to burrow into the tough Martian soil, the instrument has made progress. Three key findings have been learned so far during the mission. The seismometer detected its first marsquake in April 2019. Since that date, the Red Planet has frequently experienced quakes, but none larger than magnitude 3.7.
Seismologists on the mission say that it's surprising they haven't seen a more significant event yet. Seismologists Mark Panning says that's either luck or the fact that there have been no larger quakes may be revealing something about Mars. He believes that Mars could be more static than anticipated or InSight just landed during an especially quiet period for the planet.
Researchers believe the wind on Mars might be hiding some of the quakes Mars experiences. The team knew winds could affect the sensitive seismometer because the heavy winds shake the ground and create noise that covers up quakes. NASA says that all quakes the sensitive seismometer has detected have two sets of body waves.
Body waves that travel through the planet's interior include primary waves (P-waves) and secondary waves (S-waves). A third category of wave ripples along the top of the crust known as surface waves. The latter category is used on Earth to learn more about the planet's internal structure. However, none of the quakes detected so far have had S-waves, which is a surprise. The team believes this could be because of extensive fracturing on Mars in the top six miles of crust below InSight or that the quakes detected have originated from deep within the planet, which wouldn't produce strong surface waves. Scientists are continuing to try and solve these mysteries as the mission goes on.