Saturn is losing its rings that are headed for a graveyard
The Ring King will soon be stripped off its crown as it's losing its rings at a "worst-case-scenario" rate.
Fellas, Saturn's rings might be history soon. A new National Aeronautics and Space Administration (Nasa) research confirms that Saturn is losing its iconic rings at the maximum rate. The rings are being pulled into Saturn by gravity as a dusty rain of ice particles under the influence of Saturn's magnetic field.
Voyager 1 & 2 observations made decades ago and that has given an estimated loss rate of Saturn's rings.
"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 in Greenbelt, Maryland, said.
O'Donoghue added, "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. This is relatively short, compared to Saturn's age of over 4 billion years."
SATURN AND ITS RINGS
The boffins have long wondered if Saturn was formed with the rings or if the planet acquired them later in life.
The new research favours the latter scenario, indicating that they are unlikely to be older than 100 million years, as it would take that long for the C-ring to become what it is today assuming it was once as dense as the B-ring.
"We are lucky to be around to see Saturn's ring system, which appears to be in the middle of its lifetime. However, if rings are temporary, perhaps we just missed out on seeing giant ring systems of Jupiter, Uranus and Neptune, which have only thin ringlets today!" O'Donoghue said.
Various theories have been proposed for the ring's origin.
If the planet got them later in life, the rings could have formed when small, icy moons in orbit around Saturn collided, perhaps because their orbits were perturbed by a gravitational tug from a passing asteroid or comet.
VOYAGER OBSERVATIONS
The first hints that ring rain existed came from Voyager observations of seemingly unrelated phenomena; peculiar variations in Saturn's electrically charged upper atmosphere (ionosphere), density variations in Saturn's rings, and a trio of narrow dark bands encircling the planet at northern mid-latitudes.
These dark bands appeared in images of Saturn's hazy upper atmosphere (stratosphere) made by Nasa's Voyager 2 mission in 1981.
In 1986, Jack Connerney of Nasa Goddard published a paper in Geophysical Research Letters which linked those narrow dark bands to the shape of Saturn's enormous magnetic field, proposing that electrically charged ice particles from Saturn's rings were flowing down invisible magnetic field lines, dumping water in Saturn's upper atmosphere where these lines emerged from the planet.
The influx of water from the rings, appearing at specific latitudes, washed away the stratospheric haze, making it appear dark in reflected light, producing the narrow dark bands captured in the Voyager images.
SATURN'S RINGS: THEIR BALANCING ACT
Saturn's rings are mostly chunks of water ice ranging in size from microscopic dust grains to boulders several yards (meters) across. Ring particles are caught in a balancing act between the pull of Saturn's gravity, which wants to draw them back into the planet, and their orbital velocity, which wants to throw them outwards into space.
Tiny particles can get electrically charged by ultraviolet light from the Sun or by plasma clouds emanating from micrometeoroid bombardment of the rings. When this happens, the particles can feel the pull of Saturn's magnetic field, which curves inward toward the planet at Saturn's rings.
In some parts of the rings, once charged, the balance of forces on these tiny particles changes dramatically, and Saturn's gravity pulls them in along the magnetic field lines into the upper atmosphere.
ENCELADUS AND EXTRATERRESTRIAL LIFE
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.
Its geologic activity and water ocean make Enceladus one of the most promising places to search for extraterrestrial life.
SATURN'S SEASONS
The team would like to see how the ring rain changes with the seasons on Saturn.
As the planet progresses in its 29.4-year orbit, the rings are exposed to the Sun to varying degrees. Since ultraviolet light from the Sun charges the ice grains and makes them respond to Saturn's magnetic field, varying exposure to sunlight should change the quantity of ring rain.
(Based on reports by Nasa)