Saturn has a magnetic field almost perfectly symmetrical around its axis of rotation and unusually ordered, unlike other planets. Now we know why thanks to the study of its rings with a new analysis of the data from the Cassini probe. And we have also discovered something very interesting about its core. It occupies more than half the diameter of the planet!
One of them, of its rings, has revealed the properties of its nucleus, hidden in the depths of the golden atmosphere of the planet. And, to the surprise of scientists, it is not a core made of rock and ice, but rather it is impregnated with enormous amounts of hydrogen and helium. And not only that: it also stretches for 70,000 kilometers, essentially about 60% of the planet’s diameter, another finding that has astonished researchers, who publish their results on arXiv’s prepress service.
Specifically, they found that the core has around 17 land masses of rock and ice; But there is so much hydrogen and helium mixed in that the nucleus encompasses 55 Earth masses in total, more than half of Saturn’s total, which is equivalent to the mass of 95 Earths.
“This knowledge is important because it reflects our understanding of giant exoplanets” and indicates that giant planets in other solar systems probably have more complex structures than many researchers had thought.
How have they determined the structure of the nucleus?
Astronomer Christopher Mankovich and astrophysicist Jim Fuller, both of Caltech, examined the rings of the gas giant planet. And in the same way that earthquakes help seismologists explore the interior of the Earth, oscillations within Saturn can also help reveal its internal makeup. These oscillations alter the gravitational forces of Saturn, inducing ripples in the rings, especially in the so-called C ring, the closest to the planet of the three main rings.
The dynamo of Saturn
In another study at the same time, published in the journal AGU Advances, using computer simulations, they entered the Cassini data to try to reproduce the observed magnetic field.
Saturn’s magnetic field is almost perfectly symmetrical. How is it possible? New analysis of the Cassini data has shown what could be happening inside Saturn to produce this strange magnetosphere.
“One thing we found out was how sensitive the model was to very specific things like temperature,” explained Sabina Stanley of Johns Hopkins University. “And that means we have a really interesting probe deep inside Saturn up to 20,000 kilometers down. It’s kind of an X-ray vision.”
In addition, a convection-stable helium rain cover extending up to 70% of the planet’s radius is favorable for reproducing Cassini observations. This would explain why the interior of Saturn is also hotter than expected.
This new discovery should help planetary scientists better understand not only how giant planets formed in our solar system, but also the nature of those worlds that orbit other stars.
Referencia: C.R. Mankovich and J. Fuller. A diffuse core in Saturn revealed by ring seismology. arXiv:2104.13385. Posted April 28, 2021. / Recipe for a Saturn‐Like Dynamo C. Yan S. Stanley First published: 05 May 2021 https://doi.org/10.1029/2020AV000318
