Scientists from the United States Space Agency (NASA) maintain that they already have all the information necessary to describe the interior of Mars.
All the numbers required to understand the rocky structure internal parts of the red planet come from the InSight mission that has studied its tremors since the beginning of 2019.
The findings reveal that the thickness of the Martian crust is thinner than previously believed ; on average, it varies between 24 Y 70 kilometers,
But the information more important is the size of the nucleus of Mars. Your radius of 1, 976 kilometers is at the top of the scale of previous estimates.
This is the first time that science manages to directly map the inner layers of a planet, apart from the Earth.
The same has also been achieved with the Moon, but Mars, with a total radius of 3,390 kilometers, belongs to a much higher scale.
This kind of information allows researchers to better understand the formation and evolution of the different planetary bodies.
Similarities and differences with Earth
The mission achieved these results in the same way that seismologists study the inner layers of our planet, through the recording of signals from the tremors.
This kind of event releases waves of energy. The changes in the direction and speed of these waves reveal the nature of the rocky materials that they pass through.
The seismological system deployed by NASA observed hundreds of these movements to achieve an “image” of the Martian interior.
The instruments, in charge of scientists from the United Kingdom and France, determined that the rigid outer part or crust of the red planet below the probe has a thickness of between 20 Y 39 kilometers (depending on the precise stratification that exists).
Extrapolating this information to the known geological surface of the rest of Mars, is calculated an average between 24 Y 72 kilometres. In contrast, the average thickness of the earth’s crust is between 15 Y 20 kilometres. Only in certain regions such as the Himalayas can reach about 70 kilometers.
But the data really interesting is the core. The signs of the “marsquakes” bouncing off its metallic nature indicate that it begins almost halfway down from the surface, at a depth of about 1, 560 kilometers, and that it is in a liquid state.
Previous calculations estimated a smaller core.
No protection shields
The InSight mission team noted that two fascinating consequences can be drawn from these observations.
The first is that the known mass of Mars and the planet’s moment of inertia indicate a nucleus much less dense than previously thought, and that the nickel-iron alloy that dominates its composition must be strongly enriched by lighter elements, such as sulfur.
The second is related to the layer between the core and the crust, the mantle. This is thinner than previously thought and appears to be a simple layer of rocks without much gradation, unlike Earth.
Based on the size of Mars, it is very difficult for this mantle to be able to reach the pressures necessary for the mineral bridgmanite to become stable.
On Earth, this hard mineral covers the core, slowing down convection and heat loss. In the development of Mars, the absence of this phenomenon contributed to its rapid cooling .
Initially, this would have allowed for strong convection, which is the transport of heat through the movement of the fluid, inside the nucleus and, in addition, a dynamo effect that generated a global magnetic field.
But this has been turned off. Today no magnetic field is detected on Mars .
Yes were there, it could provide some kind of shield to protect the Martian surface from the damaging radiation that constantly arrives from space and makes the plant so uninhabitable.
An “impressive” work
“We have been able, for the first time, to look inside another planet using seismology,” he told the BBC Professor Tom Pike, from Imperial College London, and one of the main researchers of the seismological system of the InSight mission.
“What we have discovered is that Mars has a nucleus bigger and lighter than we thought, and this tells us a lot about how the planet evolved through different geological eras, ”he added.
For her part, Sanne Cottar, scientist at the University of Cambridge , who does not belong to the mission team, said that these discoveries are quite a feat, considering how difficult it is to study a small earth movement on Mars.
They never exceed a magnitude of degree 4 , something that humans would only notice if they were very close to the epicenter of the earthquake.
“Marsquakes are very, very smooth, it is much more difficult to do seismology on that planet than on ours,” he said. Cottar, and concluded:
“Mission scientists had to develop methods to work with a single seismograph located in the InSight to obtain information, and despite all these obstacles they were able to see inside the planet with the data obtained; It is really impressive”.
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