NASA has announced that its InSight lander detected what’s probably an earthquake on the planet Mars. What was nicknamed marsquake is a small earthquake that on Earth would be recorded with a magnitude of 2-2.5 and it’s only thanks to an instrument called SEIS designed for that purpose that it was detected on Mars on April 6, 2019. We’re at the beginning of Martian seismology therefore the data will be studied to confirm that it was indeed an earthquake and if that’s the case it will be the first one.
Mars doesn’t have a plate tectonics like the Earth so earthquakes are not generated by the displacement of plates and faults but by subsurface contractions caused by the cooling of the planet’s interior. This means that Martian earthquakes are far weaker than the Earth’s ones and if there were human beings on the red planet they wouldn’t even notice them. The only experiences similar to marsquakes are those of Moon earthquakes detected thanks to seismometers left by the astronauts during the Apollo missions that recorded thousands of quakes between 1969 and 1977.
The InSight lander – which landed on Mars on November 26, 2018 – is much more sophisticated because of the decades that passed since the Apollo missions and because it had to perform a series of operations on its own since the delay in communications between Mars and Earth is of some minutes so operations cannot be controlled remotely but must be programmed to be run by the on-board computer.
On December 19, 2018, InSight laid the SEIS (Seismic Experiment for Interior Structure) instrument on the Martian surface, but that was just the beginning of a long operation to place and cover the instrument with a shield that protects it from wind and temperature changes they would generate false readings. The photo (NASA/JPL-Caltech) taken on March 19, 2019, Sol 210, shows the Wind and Thermal Shield that covers the seismometer.
After the activation of the SEIS instrument, various signals were detected and three of them are still of unknown origin but they were very weak and it’s difficult to determine it. What was called the Sol 128 event since in was detected on the 128th Martian day of the InSight mission is a little stronger and longer and seems to have originated within Mars. Lori Gaze, director of NASA’s Planetary Science Division, explained that this event matches the profile of earthquakes detected on the Moon so it’s probably a Martian earthquake, or marsquake.
The SEIS instrument proved even more sensitive than expected and Charles Yana, SEIS mission operations manager the French space agency CNES, which supplied it to NASA, expressed an understandable satisfaction for the results obtained. Even the weakest events are still being analyzed because all data are important and putting them together, especially when more will be detected, perhaps it will be possible to establish their cause as well.
The surveys carried out on the Moon helped to improve our models on its formation and its internal composition, the ones just started on Mars have the same purpose. Understanding the inside of Mars will help to improve the models concerning the formation of rocky planets and to determine if when it was young the red planet actually had a liquid core that generated a magnetic field lost following the cooling of the interior of Mars.
New information on the history of the planet will also have implications in the study of the possibility that when it was young life forms emerged, consequently they’re studies that combine planetology, geology, xenobiology and more.
NASA’s JPL published a video about the possibile Martian earthquake.
