One of the primary objectives of the InSight mission is to gather information from a seismometer placed on the surface of Mars. The Seismic Experiment for Interior Structure (SEIS) listens to vibrations from within the ground, known as marsquakes, which can reveal information about the internal structure of the planet such as what the layers beneath the surface rock may be composed of.
The seismometer is very sensitive and even managed to pick up the sound of the wind on Mars from sitting on the surface. Now, the team at ETH Zurich which checks the data gathered by InSight for evidence of the quakes has recreated the experience of marsquake here on Earth.
To really give people the feel of what a marsquake might be like, the team at ETH uses a simulator room belonging to the Swiss Seismological Service (also known as a “shake room”) to replay the effects of the quakes they have detected on Mars. The signals from Mars are amplified by a factor of 10 million so that the subtle tremors can be felt in the simulator room. You can see for yourself how different the tremors are when they are based on earthquakes, moonquakes, or marsquakes.
Unlike earthquakes which have a very clear onset and end and typically between last a few seconds and half a minute, marsquakes can have much longer durations of minutes or even hours. And there are two types of marsquakes that have been observed so far: Higher frequency and lower frequency quakes. The difference between the two is likely determined by the distance of the origin of the quake from InSight.
There are plenty of questions still to be answered about marsquakes, and more data from InSight may shed light on these mysteries. “It’s a big jigsaw puzzle at this stage,” John Clinton, head of the Marsquake Service at ETH Zurich, said in the video, “and we have a long way to go before we understand it.”