Located at a distance that varies between 50 and 400 million kilometers from Earth (it depends on the distance of both planets with respect to the Sun), Mars has stimulated the imagination of humans, and the curiosity of scientists, for decades. This rocky planet is one of the most studied, not only by the probes that are sent to study its surface, but even by rovers that are currently navigating its terrain to collect clues that inform us about its past, its potential habitability and the materials. that make it up, among other data.
One of the most inaccessible mysteries of Mars is its core. As a rocky planet that it is, like Earth, we must assume that it has a metallic core. As well; What do we know about the Martian core?
Scientists believe that the core of Mars probably consists of an alloy of iron and sulfur, and to prove this, they are collecting data on the planet’s seismology. Seismic waves, similar to sound waves, can travel through the mantle of a planet, from the core to the surface, and offer a ‘view’ over the interior. But if even the core of the Earth is very inaccessible to us, even more so is that of the red planet. Direct detections of the core of Mars will probably take a long time.
Therefore, to study the nucleus of Mars, information collected by the missions launched to the neighboring planet is taken and complemented with experiments carried out here on Earth.
Keisuke Nishida is an assistant professor in the Department of Earth and Planetary Sciences at the University of Tokyo. Together with his team, he has coordinated a study to investigate the inner workings of Mars, which has been published in the journal Nature Communications on May 13.
The study was based on a series of experiments conducted on Earth of iron-sulfur alloys, believed to comprise the core of Mars, revealing details about the planet’s seismic properties for the first time. This information will be compared to observations made by Martian space probes in the near future. If the results between the experiment and the observation coincide, the existing theories about the composition of Mars will be confirmed or, on the contrary, the history of its origin will be questioned.
As Nishida explains in a press release: “NASA’s Insight probe is already on Mars collecting seismic readings. However, even with the seismic data, an important piece of information was missing without which the data could not be interpreted. We needed to know. the seismic properties of the iron and sulfur alloy believed to form the core of Mars. “
What if it’s not made of iron and sulfur?
Nishida and his team have measured the speed of what are known as P waves (one of two types of seismic waves; the other is S waves) in molten iron and sulfur alloys. Researchers reading Martian seismic data will now be able to determine whether the core is primarily an iron-sulfur alloy or not.
“If not, that will tell us something about the origins of Mars. For example, if the core of Mars included silicon and oxygen, this would suggest that, like Earth, Mars was heavily impacted when it formed, ”Nishida concludes.
So what is Mars made of and how was it formed? Probably iron and sulfur, but we can’t be completely sure yet. We may be about to find out.
References:
Keisuke Nishida, Yuki Shibazaki, Hidenori Terasaki, Yuji Higo, Akio Suzuki, Nobumasa Funamori, and Kei Hirose, “Effect of sulfur on sound velocity of liquid iron under Martian core conditions,” Nature Communications: May 13, 2020, doi: 10.1038 / s41467-020-15755-2.
