The Half-Astrophysicist Blog

Saturn’s Dancing Moons

I was away at the NSTA meeting in New Orleans and hadn’t managed to post for a few days.  I get back today and find that the Cassini Team has relased some spectacular images and movies of Saturn’s Moon’s casting shadows on the rings!

Saturn is nearing its equinox later this year.  Near the equinox is the only time you can see moon shadows cast on Saturn’s rings and we have NEVER had a spacecraft at Saturn to capture these images before!  This image shows Saturn’s moon Epimetheus as its shadow moved across the rings over the course of about an hour.  Click on the image to see a larger, flash version of the animation.

Since the rings are almost edge on to the Sun, the shadows cast by the Moons are very long.  If you could stand on a particle in the rings, the Sun would be very low in the sky right now.  Shadows grow long.  You can do this yourself here on Earth.  Take a large ball outside a few minutes before sunset. Hold it up and look at its shadow.  You will see the shadow of the ball is not round, but long and thin.  We are seeing an extreme case of this phenomena here.

We knew this should happen based on the geometry for many years.  Now we finally get to see it!

March 23, 2009 - Posted by | Uncategorized

No comments yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: