New NASA research indicates that Saturn’s
iconic rings are not only younger than previously
thought, but also that these rings are actually
disappearing.
The research found that the rings are draining
away toward the planet as a dusty rain of
ice particles.
Saturn’s rings consist mostly of water ice
and dust that ranges in size from microscopic
particles to large boulders.
Ultraviolet light from the Sun and plasma
clouds coming from tiny meteoroid strikes
charge the icy dust, which then becomes attached
to Saturn’s magnetic field and pulled into
the planet by gravity.
This charged material rains down onto the
planet and begins to disintegrate, allowing
it to react chemically with the electrically
charged part of Saturn’s upper atmosphere
- known as the ionosphere.
Using observations from instruments attached
to the Keck Telescope in Hawai’i, the ions
were seen to glow brightly in the infrared
if the rain was light, but these emissions
were dim if the rain was heavy.
So if the rings are disintegrating, how much
longer will they be around?
Based on the rate of disappearance of Saturn’s
rings observed by Keck, astronomers infer
that they must have formed only 100 million
years ago.
This means Saturn didn’t always have them,
because the planet itself is over four billion
years old.
Further, when the Keck ring rain data is combined
with observations made by the Voyager 1 and
2 missions, scientists estimate that Saturn’s
rings will be gone in 300 million years.
