Saturn has a “fuzzy” core, revealing ring ripples

A team of astrophysicists examining data from the Cassini probe’s tour of Saturn has estimated athis size for the core of the planet. Study the gravitational effects on the iced rings, the team determined that Saturn’s core is a combination of ice, rock, hydrogen, and helium about 50 times more massive than Earth, making it much more diffuse than previously thought.

“The conventional image has it that the interior of Saturn has a sharp division between a compact core of rock and ice. and an envelope composed mainly of hydrogen and helium. We found that unlike this conventional picture, the core is in fact ‘vague’: all of those same rocks and ice are there, but they are indeed blurry over much of the planet, ”said Christopher Mankovich, a researcher at the California Institute of Technology and lead author of a paper on the findings, published today in Nature Astronomy.

The rocks and ice inside Saturn are slowly giving way to the more gaseous parts of the planet as you move away from the core, he said.. The team discovered that the kernel did not have a clearly defined endpoint; rather, it had a transition region which represented about 60% of all the diameter of Saturn, making the nucleus a huge part of the total size of the planet and a much larger part than the 10% at 20% the diameter of a planet than a more compact nucleus would be.

Previously, Saturn was thought to have a rocky, metallic core under all that icy, fluid gas. “When observations were limited to traditional gravity field data, the compact core model did a good job,” Mankovich said, but the more recent data from Cassini gave us a different and better picture of inside. the planet. As National Geographic reported in 2015, the idea of ​​studying the interior of Saturn using its rings has been circulating for several decades. But Cassini, in his 13 years of flight through the rings of Saturn (before it ran out of fuel in 2017) provided the real data on these dazzling structures and the processes that take place within them.

Saturn can be thought of as a giant space mixer, spinning its building blocks of ice, rock and gas which in some places are so cold that they behave like fluids. The surface of the planet is moving a bit in all the hubbub — about 3 feet every two hours, placid for an object of its size – and this oscillation causes fluctuations in the gravitational field of the planet, which extends outward spirals towards the rings of the planet, warping them. The icy particles that make up Saturn’s rings move in response to these gravitational changes due to the planet’s interior, equivalent to seismic activity for a planet that is not rocky.

The rings are a blueprint for astrophysical research which makes Unique Saturn among other gas giants, such as Jupiter, which lacks such a useful access point tinside. Mankovich said the new findings on Saturn adds credit to the idea that the evolution of gas giants is a gradual process, starting with building a nucleus from the coagulation of chunks of space rock, then proceeding with the accumulation of gases to form the rest of the planet.

It is only the last in what was a string of characters of knowledge by Cassini on the Saturnian interior and the processes that could be induced. More Cassini data on other oscillations have yet to watch, and mysterious accelerations felt by the spacecraft in the later stages of its operation have not yet been explained. It may be some time before we return to Saturn with another spaceship (projectors are currently on Venus and Mars), but luckily Cassini left the astrophysicists with their hands full.

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