The waves in the rings reveal the structure of the planet’s core

pasadena – Saturn’s core is much larger and more diffuse than previously thought. This is the result of an analysis of wave propagation in the giant planet’s ring, as reported by scientists in the journal Nature Astronomy. Measurements must also show that the nucleus consists of a different mixture of elements than previously assumed.

“So far, measurements of their gravitational field have given us the best insight into the giant planet’s internal structure,” wrote Christopher Mankovich and Jim Fuller of the California Institute of Technology in Pasadena. To do this, scientists compare the spacecraft’s trajectory around the planet with the predicted planetary structure models. “However, these data must be very sensitive to the planet’s outer layers, while measurements of the mass and compactness of the core are nearly impossible.”

Thanks to its extensive ring system, Saturn offers researchers another opportunity to study the planet’s internal structure: fluctuations in the giant planet’s gravitational field. Mankovich and Fuller have now reassessed the “Cassini” data, correlated it with Saturn’s gravitational field, and analyzed which internal structures match the observations.

Their results were surprising: according to them, the nucleus extended to 60% of the planet’s radius, making it much larger than previously thought. If astronomers had previously suspected that the nucleus was made of heavy elements and surrounded by a well-defined envelope of hydrogen and helium, they should also revisit this idea: Saturn’s ring oscillations could not be explained, only if the nucleus consisted of a mixture of these elements. heavy elements Elements containing hydrogen and helium, which gradually change from the inside out. The transition from the core to the shell does not occur at a clear boundary, but is diffuse.

This internal structure poses a challenge to current models of planet formation, according to Mankovich and Fuller. But it could provide valuable insight into how Saturn’s core formed from gas, dust, and rock in the young solar system.

Saturn’s most striking feature is Saturn’s ring system. Galileo Galilei was the first to see it through the telescope he had developed as early as 1610, but described it as a kind of handle, and not as an isolated ring. Today we know that the main ring of different colors consists of more than one hundred thousand individual rings. The deepest begins about 7,000 kilometers from Saturn’s surface and has a diameter of 134,000 kilometers. The furthest is 960,000 kilometers away.

With a thickness of up to several hundred meters, the individual rings are very thin. They are made up of chunks of ice and rock – from the size of dust particles to a few feet in diameter. In the ring area, there are also so-called shepherd moons such as Prometheus and Pandora. (dpa / fwt, BLZ)

–