NASA’s “Insight” probe reveals the secrets of the internal structure of Mars

With this information, researchers can better understand the formation and evolution of different planetary bodies.

“Insight” uses the same method that seismologists study the stratification of the Earth’s interior, that is, it achieves results by tracking vibration signals.

These vibrations release energy waves and changes in the path and speed of the energy waves will reveal the nature of the rocky material that it passes through.

The seismograph system deployed by the NASA probe has observed hundreds of vibrations. In the last two years, some vibrations have the right characteristics that can be considered as internal images of Mars.

The French and UK-led instrument team determined that the tough outer crust of Mars is 20 kilometers or 39 kilometers thick directly below the probe (depending on the precise layers at the location). Combined with known surface geology from other parts of Mars, the average thickness is inferred to be between 24 kilometers and 72 kilometers. In contrast, the average thickness of the earth’s crust is 15 to 20 kilometers. Only in continental areas like the Himalayas can it reach 70 kilometers.

But the really interesting figures refer to the core of the earth. The signal bounced from the “Martian Shock” to the instrument showed that it was in a liquid state from the surface of Mars to a position of about 1,560 kilometers. Most previous estimates believe that the core of Mars is relatively small.

The task force said that there were two interesting results from the new direct observations.

First, the known mass and moment of inertia of Mars means that the density of the Martian core will be much lower than previously predicted, and the dominant component of Mars, the alloys of iron and nickel, must be rich in elements. lighter like sulfur.

The second result is related to the layer between the core and the crust: the mantle. This layer is now thinner than previously assumed and appears to be different from earth. This layer is made up of stones without large gradients.

Based on the known size of Mars, the height of this mantle pole is unlikely to reach the pressure that stabilizes the mineral Richmanite.

In the ground, this hard mineral covers the center of the earth, slowing down convection and heat loss. Therefore, in the initial stage of the formation of Mars, the absence of this mineral led to a rapid cooling of the temperature.

Initially this would allow the strong convection of the metallic core and the generating effect that drives the global magnetic field. But of course this no longer exists. Today, the global magnetic field cannot be detected on this planet.

If it exists, it will provide some shielding to protect its surface from the destructive radiation that continues to fall from space, making the world extremely uninhabitable.

Professor Tom Pike of Imperial College London is one of the principal investigators of the InSight seismograph system. He told the BBC: “For the first time we can use seismology to look inside another planet. What we see on Mars is that we have a larger and lighter core than expected. This tells us a lot about this planet during the period. Geological. Information on Evolution “.

Dr Sanne Cottaar from the University of Cambridge is not on the working group. She described the result of “Insight” as a feat because it is very difficult to study the tiny vibrations that occur on Mars. They have never exceeded level 4 and humans will only notice them a few kilometers from the epicenter.

She said: “Martian earthquakes are very, very weak. This is much more challenging than doing seismology on Earth. The mission scientists also had to develop a seismograph that the InSight detector can use. So look at this data, and it’s very encouraging to be able to use this data to look at the internal structure of Mars. “