Science

Saturn's rings could vanish much sooner than expected

Saturn's rings could vanish much sooner than expected

The innermost rings disappear as they rain onto the planet first, very slowly followed by the outer rings. A 1986 paper in the journal Geophysical Research Letters sought to explain this, theorizing that the ring particles were becoming entrained in Saturn's magnetic field, plunging toward the planet and creating what amounted to a "ring rain", which cleared away haze and created the signature lines. Using a telescope, you can see even more moons and Saturn's rings tilted at 26 degrees.

NASA released a pretty fantastic GIF of Saturn, showing the transition from what it looks like today to what it will look like towards the end of the rings' lifespan.

"We estimate that this "ring rain" drains an amount of water products that could fill an Olympic-sized swimming pool from Saturn's rings in half an hour", James O'Donoghue of NASA's Goddard Space Flight Center said in a NASA press release on Tuesday.

And although 100 million years might sounds like a long way off, the time span is comparatively short compared to Saturn's age of over 4 billion years. The team looked at previous research about the planet's "ring rain" that tracked how much mass was being lost.

Once there, the icy ring particles vaporize and the water can react chemically with Saturn's ionosphere.

Based on a new research paper, penned by O'Donoghue and six other researcher from institutions across the U.S. and United Kingdom, the combined effect of these two mechanisms is causing ring material to rain down onto Saturn at what NASA calls the "worst-case-scenario" rate of the estimates provided by the Voyager data.

NASA has put together a nice video of the interaction of the rings with the planet to give more detail.

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The research has also provided evidence to solve another mystery: when and how Saturn's rings appeared.

The current working theory is that Saturn acquired its lovely rings later in its lifespan of roughly four billion years and that its (relatively) new-found bling "only" showed up about 100 million years ago.

"If rings are temporary", O'Donoghue said, "perhaps we just missed out on seeing giant ring systems of Jupiter, Uranus and Neptune".

Various theories have been proposed for the ring's origin.

The Cassini spacecraft captured this stunning view of Saturn and its rings on April 25, 2016.

There are still some unanswered questions in the case of the disappearing rings. This balance gets perturbed when ice particles are charged by the Sun's ultraviolet light, causing the particles to plummet down toward the planet along its magnetic field lines, with gravity providing an added boost. This is where Saturn's magnetic field intersects the orbit of Enceladus, a geologically active moon that is shooting geysers of water ice into space, indicating that some of those particles are raining onto Saturn as well. The researchers also made the surprising discovery of a glowing band at a higher latitude in the planets southern hemisphere. "That wasn't a complete surprise", said Connerney. This mosaic shows everything from the expansive rings to the hexagonal jet stream at the north pole. Pandora, which is about (52 miles, 84 kilometers) wide, was on the opposite side of the rings from Cassini and Enceladus when the image was taken.

At any given moment, the majority of the water ice grains that form Saturn's rings maintain a stable trajectory.