1. Saturn’s Rings

2. Handles, Rings or Rocks?
Saturn’s Rings were first thought to be attached like handles.
In 1659 Christian Hugyens observed that they were rings Detached from the planet.
The Rings were thought to be thin sheets of material
In the mid 19th century James Clerk Maxwell showed mathematically that the rings could not be solid, but must be made of particles
Spectroscopes confirmed this by detecting that different parts of the rings moved at different speeds, obeying Kepler’s Laws for Planets

3. Kirkwood gaps & “Shepherd Moons”
Ring Structure
There are many rings divided by gaps.
The particles that make-up the rings increase in size with distance from Saturn
Two large gaps divide the rings into three main rings
The largest gap,
“Cassini’s Gap”
is named after its discoverer
Kirkwood gaps & “Shepherd Moons”
In 1866 Daniel Kirkwood discovered that gravity from some of Saturn’s moons create the gaps and define the limits of the rings

4. The Roche Limit
There is a distance from a Planet at which the tidal forces from the planet will tear an object of the same density apart.
It is called the Roche Limit and is about about 2.44 times the radius of the planet.
Saturn’s Rings extend little more than twice its radius.
Rings are composed of the debris of moons, asteroids, or even comets that
Came too Close!
Here we see the comet Shoemaker-Levy torn apart after getting too close to Jupiter