Beneath Mars’ surface uncovered
The Rice University seismologists have made a major breakthrough using NASA’s InSight Lander on Mars. They have made the first direct measurements of three subsurface boundaries from the crust to the core of Mars. Ultimately it may help us understand planetary formation, said Alan Levander, co-author of a study published this week in Geophysical Research Letters. There have been others who have calculated the thickness of the Red Planet and the depth of its core. However, Levander feels that the direct measurements recorded using InSight’s data can be used in models which will result in an improvement.
- In the absence of plate tectonics on Mars, its early history is mostly preserved compared with Earth. The depth estimates of Martian seismic boundaries can provide indications to better understand its past as well as the formation and evolution of terrestrial planets in general.
- The InSight lander’s main objective has been to listen to the faint rumblings inside our neighbouring planet.
- This is only possible because of the dome-shaped seismometer on the robotic lander that touched down on Mars in November 2018.
- These faint rumblings can be compared to how a doctor listens to a patient’s heartbeat using a stethoscope.
- The data recorded on InSight’s seismometer is from February to September 2019 which includes more than 170 vibrations from seismic waves which can be caused by meteor strikes or marsquakes (like an earthquake).
Boundaries that were found within the inner structure of Mars
- Located 22 miles beneath the surface, a divide between the crust and the mantle which is “a transition within the mantle from an area where magnesium iron silicates form a mineral called olivine to one where they form wadsleyite.
- The second one was found between 690 miles and 727 miles beneath the surface of Mars.
- The third one was found between 945 miles and 994 miles beneath the surface which is a divide between the mantle and core.
- The traditional way to investigate structures beneath Earth is to analyze earthquake signals using dense networks of seismic stations.
- Mars is much less tectonically active, which means it will have far fewer marsquake events compared with Earth. Moreover, with only one seismic station on Mars, we cannot employ methods that rely on seismic networks.