The earlier presence of liquid water on the surface of Mars, partly due to the presence of a magnetic field, is well known today, but the reasons for the disappearance of this shield about 4 billion years ago are unclear. By recreating the conditions prevailing at the center of Mars, a team of Franco-Japanese researchers suggests that its combination, over time, will bring about a cessation of convection events in the form of a magnetic field.
On earth, it is a protective shield for life: (Flow of charged particles) will break down our structure And corrosive . It is believed to have played a key role in the existence of Mars On the surface, allowing to maintain a dense atmosphere; But the Mars magnetic field did not last long, as evidenced by some magnetized rocks with traces of the effects of the past magnetic field.Protects us from interplanetary space, in particular
How does the magnetic field work?
The center of Mars is less dense than Earth
Based on seismic data recorded by Lander Of , As well as the composition of the Martian meteorite, we can estimate the internal structure of Mars. Therefore, the Martian center appears to have a relatively low density, indicating that it may be saturated with sulfur and light elements. Mix with liquid iron.
To simulate the behavior of the Mars Center in the laboratory, the scientists based themselves on this estimate: they placed a sample of a mixture of iron, sulfur, and hydrogen between the two.Compressed (to simulate pressure conditions at the center of Mars) and under laser radiation (To simulate the temperature of the center of Mars).
Strange behavior in the gut of Mars …
By observing the exposed model to the conditions of Mars’ X-ray center, scientists were able to observe its variations. And its composition. Their observations revealed that the mixture of iron, sulfur and hydrogen had a peculiar behavior: initially homogeneous, the sample was separated into two distinct liquids, one enriched with sulfur and the other enriched with hydrogen. According to scientists, this is it Between these two fluids there would have been the appearance of a magnetic field on Mars, but it would have disappeared prematurely.
The hydrogen-enriched liquid iron phase, which is less dense than the sulfur-enriched liquid iron phase, rises gradually more than the latter, causing convection motions as it passes. These currents, like terrestrial convection currents, favor the appearance of a magnetic field in the early stages of Mars’ history, allowing liquid water to survive on its surface. But these convection currents are not destined to remain constant: once the two liquid states are completely separated, there is no machine to create motions in the center. The Then scattered, and the Martian atmosphere will emerge later About 4 billion years ago.