Saturn hasn't always had rings

In its last days, the Cassini spacecraft looped between Saturn and its rings so that Earth-based radio telescopes could track the gravitational tug of each. Scientists have now used these measurements to determine the mass of the rings and estimate its age, which is young: 10-100 million years. This supports the hypothesis that the rings are rubble from a comet or Kuiper Belt object captured late in Saturn's history.

from Latest Science News -- ScienceDaily http://bit.ly/2W3czwy