New Studies Reveal Saturn's Rings Could Disappear 1:15

(CNN) -- Saturn's iconic icy rings could cease to exist in the future for skywatchers who gaze at them through their telescopes, according to new research.


A new analysis of data captured by NASA's Cassini mission, which orbited the gas giant planet between 2004 and 2017, revealed new data on how long the rings have existed and when they might disappear from view. The findings were shared in three studies published in May.

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Our solar system and its planets formed about 4.600 billion years ago, and scientists have long debated the age and origin of Saturn's rings. Some astronomers argue that the bright, icy rings must be younger than expected because they have not been eroded and obscured by interactions with meteoroids over billions of years.

Cassini's data have led to a new finding, published May 15 in the academic journal Icarus, that supports this theory that the rings appeared long after Saturn's initial formation. Other studies published May 12 in Science Advances and May 15 in Icarus, respectively, reached similar conclusions.

"Our inescapable conclusion is that Saturn's rings must be relatively young by astronomical standards, at just a few hundred million years old," Richard Durisen, professor emeritus of astronomy at Indiana University Bloomington and lead author of both studies published in Icarus, said in a statement.

"If you look at Saturn's satellite system, there are other indications that something spectacular happened there in the last few hundred million years. If Saturn's rings aren't as old as the planet, that means something happened to form its incredible structure, and that's very exciting to study."

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According to the researchers, it is likely that the seven rings were still in formation when dinosaurs roamed the Earth.

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Saturn's rings

Saturn's rings are composed mostly of ice and only a small percentage belong to the rocky dust created in space by broken fragments of asteroids and micrometeoroids. These fragments, similar to grains of sand, collide with particles from Saturn's rings and create floating debris as the ring material orbits the planet.

During Cassini's grand finale, when the spacecraft completed 22 orbits in which it passed between Saturn and its rings, the researchers were able to obtain data on how many meteoroids contaminate the rings, the mass of the rings themselves, and the speed at which ring material rains down on the planet. All the data seemed to point to the same conclusion about the younger age of Saturn's rings.

Saturn's rings are made up of ice particles the size of grains of sand or rocks. The ring system extends up to 282,000 kilometers from the planet. Credit: NASA/JPL-Caltech/Space Science Institute

The researchers were able to determine how much cosmic dust accumulates in the icy rings. Over the course of 13 years, Cassini's Cosmic Dust Analyzer was able to pick up 163 dust grains from beyond the Saturn system as they revolved around the gas giant. The rings were surprisingly "clean," suggesting that they must not take so long as to accumulate excess cosmic dust.

Meanwhile, as meteoroids infiltrate the rings, they push material from the innermost rings toward Saturn at high speed. Cassini observed that the rings were losing many tons of mass per second, meaning they don't have much time left, astronomically speaking. The researchers estimate that the rings will only last a few hundred million years at most.

Previous research had suggested that the rings could disappear in 100 million years.

The new theory about what Saturn's rings would be 0:57

Enduring Mysteries

"We've shown that colossal rings like Saturn's don't last long," Paul Estrada, a research scientist at NASA's Ames Research Center in Mountain View, California, and a co-author of the three studies, said in a statement.

"It can be speculated that the relatively faint rings surrounding our solar system's other gas and ice giants are remnants of once-colossal rings like those on Saturn. Perhaps sometime in the not-too-distant future, astronomically speaking, after Saturn's rings shrink, they will look more like Uranus' sparse rings."

Cassini captured a backlit view of Saturn while in the planet's shadow in December 2012.
Credit: NASA/JPL-Caltech/Space Science Institute

It's possible that the dark rings around Neptune and Uranus were larger and brighter in the past, similar to how Saturn's rings are now, the researchers said.

But what gave rise to Saturn's rings? Scientists don't yet know for sure, but it's possible that gravitational instability destroyed some of the icy moons orbiting the giant planet, creating enough material to be dragged along and form the rings of material surrounding Saturn.

"The idea that Saturn's iconic main rings could be a recent feature of our solar system has been controversial, but our new results complete a trifecta of Cassini measurements that make this finding hard to deny," researcher Jeff Cuzzi, principal investigator at NASA Ames and co-author of the Saturn research paper that appeared in Science Advances, said in a statement.

Future missions to study some of Saturn's moons could reveal more information about what events created the rings, and lead to other discoveries.

"If we can figure out what happened in that system a few hundred million years ago to form the rings, we may end up figuring out why Saturn's moon Enceladus is ejecting plumes of water, ice and even organic material from its deep ocean," Durisen said. "We may even end up finding the building blocks of life itself on Enceladus."

Saturn