An international research team used seismic data from NASA’s Mars Insight probe to make direct measurements of the properties of the Martian core. It was established that this core is liquid and consists of ironslug With a large proportion of sulfur and oxygen. The new findings provide more insight into the formation of Mars and the geological differences between it and Earth (PNAS24 April).
To determine these differences, scientists tracked the trajectory of two seismic events on Mars — one caused by a tapering earthquake and the other by a large impact — and discovered waves that passed through the core of the planet. They measured the time it took for these waves to propagate through Mars, and compared them to waves that remained within the planet’s mantle (the layer just below the crust). By combining this information with other seismic and geophysical measurements, the researchers were able to determine the density and compressibility of the material the waves experienced. The results indicate that Mars, unlike Earth, has a completely liquid core. Earth’s core is a mixture of a liquid outer core and a solid inner core.
In addition, the team learned more about the chemical composition of the Martian core, which appears to contain a surprisingly large amount of light elements, mainly sulfur and oxygen. The measurement results indicate that the mass share of these elements is about twenty percent. This high proportion differs greatly from the relatively low fraction of light elements in the Earth’s core, indicating that the Martian core is less dense and more compressible than the Earth’s core. From this, scientists concluded that the conditions in which the two planets were formed differed greatly.
While Mars does not currently have a magnetic field, residual traces of magnetism in the planet’s crust indicate that a magnetic shield, similar to the field created by Earth’s core, was once present. According to the researchers, this could mean that Mars was initially a “habitable” planet and gradually turned into a somewhat hostile desert world. Its internal conditions and the great influences on its surface were decisive factors. (EE)
Scientists have detected seismic waves traveling through the Martian core for the first time
