The waves of Saturn’s rings reveal the nature of its essence

Madrid, 16 years ago. (European Press) –

Oscillations inside Saturn cause the gas giant to move slightly. These movements, in turn, cause ripples in the rings of Saturn.

In a new study accepted in the journal Nature Astronomy, two astronomers from the California Institute of Technology analyzed these undulating rings to reveal new information about Saturn’s core. In their study, they used data captured by NASA’s Cassini mission, a spacecraft that orbited the ringed giant for 13 years before plunging into the planet’s atmosphere and disintegrating in 2017.

The results indicate that the core of the planet is not a ball of solid rock, as some previous theories have suggested, But an inconspicuous soup of ice, rock, and mineral fluid, or what scientists call a “mysterious coreThe analysis also reveals that the core extends more than 60 percent of the planet’s diameter, making it much larger than previously estimated.

“We use Saturn’s rings as a giant seismometer to measure oscillations inside the planet,” he says. It’s a statement Co-author Jim Fuller, assistant professor of theoretical astrophysics at Caltech. “This is the first time we have been able to seismically investigate the structure of a gas giant planet, and the results are very surprising.”

“Detailed analysis of Saturn’s undulating rings is a very elegant form of seismology for inferring the characteristics of Saturn’s core.Jennifer Jackson, a professor of mineral physics at Caltech’s Seismological Laboratory, said in a statement that she was not involved in the study but uses different types of seismic observations to understand the composition of Earth’s core and to identify possible seismic events on Venus in the future. .

The study’s lead author is Christopher Mankovitch, a postdoctoral researcher in planetary sciences working in the Fuller Group.

The results provide the best evidence to date of Saturn’s diffuse nucleus and are consistent with recent evidence from NASA’s Juno mission, which indicates that The gas giant Jupiter may also have a similarly dilute core.

“Fuzzy cores are like mud,” Mankovic explains. “Hydrogen and helium on the planet gradually mix with more and more ice and rock as it moves toward the center of the planet. It’s a bit like parts of Earth’s oceans where salinity increases as they get deeper and deeper, creating a stable formation. “

The idea that Saturn’s vibrations could generate ripples in its rings, and thus that the rings could be used as a seismometer to study the interior of Saturn, first appeared in studies in the early 1990s by Mark Marley and Carolyn Porco, who later became Cassini. Photography team leader. The phenomenon was first observed by Matt Hedman and PD Nicholson in 2013, who analyzed data captured by Cassini. Astronomers found that Saturn’s C ring It contained multiple spiral patterns driven by fluctuations in Saturn’s gravitational field And that these patterns were distinct from other ripples in the rings caused by gravitational interactions with the planet’s moons.

Now, Mankovic and Fuller have analyzed the wave pattern in the rings to build new models of Saturn’s sparse interior.

“Saturn is always vibrating, but it’s subtle,” says Mankovitch. “The surface of the planet moves about a meter every hour or two like a slowly undulating lake. Like a seismograph, The rings pick up gravitational disturbances and the ring particles start moving“, Dice.

The researchers say that the observed gravitational waves indicate that Saturn’s deep interior, as it moves as a whole, consists of stable layers formed after heavier material sank into the middle of the planet and stopped mixing with lighter material above it.

“For the planet’s gravitational field to oscillate with these particular frequencies, the interior must be stable, This is only possible if the fraction of ice and rock gradually increases as you move towards the center of the planet‘, Dice Fuller.

Their results also indicate that Saturn’s core is 55 times the mass of the entire Earth, with 17 masses of ice and rocks and the rest being a liquid of hydrogen and helium.

Hedman, who is not part of the current study, says: “Christopher and Jim were able to show that a characteristic of the ring In particular he provided strong evidence that Saturn’s core is very diffuse. I’m excited to think about all the other features of the ring created by Saturn that could tell us about this planet.”

In addition, the results pose challenges to current models of giant gas formation, which argue that shale cores form first and then attract large envelopes of gas. If the cores of planets are really confused, the study suggests, Planets can incorporate gas early in the process.