Extremely sensitive instrument of the InSight mission captures vibration of seismic waves on the surface of the red planet; listen to the recording
By A. J. Oliveira
4 Oct 2019, 11:00 – Posted 4 Oct 2019, 10:59
If a person lay on his side on the surface of Mars and put his ear to the red soil, he would most likely not hear anything. From time to time, the bowels of the red planet "sing". Only the only way to hear the music from the depths of the neighboring world is to have a very, very accurate hearing. Lucky for us, NASA has a probe, InSight, which has been doing just that for almost a year.
The main scientific objective of the mission operated by the Jet Propulsion Laboratory (JPL) is to conduct studies with unprecedented level of detail about the deep interior of Mars. Its instruments, mostly built by European partner institutions, are intended to make careful measurements of seismic activity to obtain accurate 3D models of the planet's internal structure, as well as to measure heat propagation in the Martian subsoil.
These studies will open many doors not only for understanding the geological past of Mars, but also for gaining valuable insight into the formation and evolution of all other terrestrial planets in the Solar System – Mercury, Venus, Earth, and even our Moon. , an instrument of the spacecraft stands out: it is the SEIS, made by the French space agency. It is a high sensitivity seismometer that listens to "tidal waves".
So keen, he is able to pick up on the subtle vibrations caused by Martian breezes, as well as record the crackles and creaks of InSight's own parts. By studying how seismic waves propagate, scientists can understand for the first time details about the structure of the deep red planet. So far, more than 100 events have been detected by the scientific team, of which 21 are considered earthquakes.
Two of the most significant were recorded on May 22, magnitude 3.7, and on July 25, magnitude 3.3. Both indicate that the crust of Mars is more similar to that of the moon than that of Earth. Here the cracks end up being sealed over time thanks to the action of water, which carries sediment and closes the holes; on the moon and on Mars, this does not happen, so the sound waves of tremors spread much more fragmented through the ground.
While on earth seismic waves last a few seconds, on our natural satellite and in the neighboring world they can last for a few minutes. There are likely to be more earthquakes in the catalog of sounds collected so far, but scientists have yet to rule out other possible causes for the noises. Because they have to deal with an extremely sensitive ear, it is very complicated to separate the chaff from the wheat. Listen to one more recording:
Over time the team became accustomed to the different sounds, learning to recognize each noise and filter out the background noise. They report that the best time to listen to the "tidal waves" is at dusk and night, when there is less wind from the warm air during the day. All this sound intimacy even made the team feel even closer to the spacecraft, as if they were really on Mars.