Following a Moon Shadow


A Traveling Shadow
A Traveling Shadow

I assembled this animation from 20 separate raw images, taken by Cassini on April 9th. It follows the elongated shadow of a moon, most likely Epimetheus (not officially specified), across the tops of Saturn’s rings.

Beginning on the bright B ring the shadow moves across it, over the darker bands of the Cassini division, then crosses the even brighter A ring, including the channels of the Encke Gap and narrower Keeler Gap before disappearing off the edge before the thin F ring. Images like this are possible because of the current angle of Saturn relative to the sun…it is closely approaching its spring equinox when, on August 11, its ring plane will be perpendicular to its orbit. This causes several of its moons to cast shadows directly onto the rings. This is a real treat, since Saturn’s 29-year-long seasonal cycle doesn’t offer up views like this often (and it hasn’t had its own personal paparazzi in quite some time either!) 

Cassini was over 735,000 miles from the rings when these images were taken.

Raw image credit: NASA/JPL/Space Science Institute.


  1. Bill says:

    Amazing. Nice work.


    1. J. Major says:

      Thanks Bill. Really, I let Cassini do most of the work. 😉


  2. Kim says:

    Very cool.


  3. Jason says:

    @ bill kim – agreed!


Comments are closed.