New NASA research indicates that Saturn’s iconic rings are not
only younger than previously thought, but also that these
rings are actually disappearing at an extremely fast pace. 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 that ranges in size from microscopic
dust to large boulders. Ultraviolet light from the Sun
and plasma clouds coming from tiny meteoroid strikes charge
the icy dust, which then becomes bound to Saturn’s magnetic field
and pulled into the planet by gravity. This material rains
into the planet and begins to disintegrate, allowing it to
react chemically with the electrically charged part of
Saturn’s upper atmosphere - the ionosphere. The ions glow in an
infrared light as a part of this process if the rain is light,
but the emissions dim if the rain is heavy. This was observed
using instruments attached to the Keck telescope in Hawaii.
The rate of disappearance in this ring rain study has allowed
scientists to infer that Saturn’s rings formed less than
100 million years ago. This means Saturn wasn’t born this
way, as the planet is known to be over 4 billion years old. And
when the ring rain data is combined with observations made
by the Voyager 1 and 2 missions, scientists from NASA Goddard are
able to estimate that the rings will be gone in 300 million
years. So, if this rain doesn’t go away, Saturn will be
ring-less another day.