NASA has confirmed that Saturn’s rings are disappearing at the worst-case scenario rate estimated from the Voyager 1 and 2 observations decades ago.
Saturn’s rings are being pulled into Saturn by gravity, acting as a dust of ice particles under the influence of Saturn’s magnetic field.
James O’Donoghue of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said: “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. 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.”
The origin of Saturn’s rings
It is unknown whether Saturn was formed with its rings or if the planet acquired them later.
Various theories have been proposed for the origin of Saturn’s rings. If they were acquired later in life, the rings might have formed when small, icy moons orbiting Saturn collided due to the gravitational pull from a passing asteroid or comet.
The new NASA research supports the theory that Saturn’s rings were formed later in its life, indicating that they are unlikely to be over 100 million years old because it would take that long for the C-ring to become what it is today, if it had previously been as dense as the B-ring.
O’Donoghue added: “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!”
Video credit: © NASA Goddard
The next step for this research would be for the team to see how the ring rain changes with the seasons on Saturn.