Published: Wed, December 19, 2018
Sci-tech | By April Francis

Saturn is losing its rings

Saturn is losing its rings

The discovery was made based on observations from NASA's probes Voyager 1 and 2, which had encounters with Saturn on their way to the outer Solar System in November 1980 and August 1981, respectively.

The planet's magnetic field is causing the rings to be pulled inward by gravity, creating a dusty rain of ice particles.

Saturn's rings are being dragged into its main body by gravitational pull from the planet.

"What we're seeing is something on the order of about a ton and a half per second", said James O'Donoghue of NASA's Goddard Space Flight Center, in Greenbelt, Maryland, who reported the conclusions Monday in the journal Icarus. "From this alone, the entire ring system will be gone in 300 million years, but add to this the Cassini-spacecraft measured ring-material detected falling into Saturn's equator, and the rings have less than 100 million years to live".

That's a snap of the fingers in cosmic time, particularly considering Saturn is more than 4 billion years old. O'Donoghue and his colleagues theorized that the ring rain begins when ring particles become electrically charged, either by ultraviolet energy from the sun or by plasma-hot, charged gas generated when micrometeoroids bombard Saturn's atmosphere. They detected some unusual changes in Saturn's ionosphere, density variations in the rings themselves, and three dark bands circling Saturn at mid-northern latitudes.

Earlier this year, the team took a close look at measurements of a charged molecule found in the upper reaches of Saturn's yellowish atmosphere, using the Keck II Telescope in Hawaii in 2011.

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

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

Scientists estimate the rings could be gone in 300 million years, but they could vanish even faster.

The culprit: "ring rain", a phenomenon in which particles and gases fall into the planet's atmosphere.

"We know that it's bumping material out of the rings at least 10 times faster than we thought", said Thomas Cravens, co-author of one of the October studies and a University of Kansas professor of physics and astronomy. The fact is that Saturn is rapidly heading towards another ring-free phase of its life.

Their observations revealed glowing bands in Saturn's northern and southern hemispheres where the magnetic field lines that intersect the ring plane enter the planet. The geysers, first observed by Cassini instruments in 2005, are thought to be coming from an ocean of liquid water beneath the frozen surface of the tiny moon. This view looks toward the night side on Pandora as well, which is lit by dim golden light reflected from Saturn.

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

Like this: