Cassini's Indirect Image of Boulders and Moonlets in Saturn's Rings

By Nancy Atkinson - April 12, 2009 at 7:51 PM UTC | Planetary Science
saturn-ring-shadows-1.jpg

[/caption] Take a look at this -- it is absolutely stunning. A couple of weeks ago,

Anne wrote an article about moon shadows on Saturns rings.

Because Saturn is approaching its equinox, in August the rings will "disappear" from our view from Earth, as the rings will be exactly edge-on. But as the rings ease into alignment with the sun, Saturn's moons cast their shadows across the rings, growing longer as equinox approaches. See in the image above, a shadow is cast on the rings, likely by either the moon Mimas or Tethys. But the eagle-eyed folks over at

UnmannedSpaceflight.com

also noticed something else in this raw image from the Cassini spacecraft. Notice the area right near the middle of the image where the rings look kind of fuzzy? That's not just camera blur; those are more shadows, created by

thousands of boulders or moonlets in the ring!

Amazing! We've never actually seen the small objects that make up the rings -- and we still haven't -- but we're seeing

the shadows they are creating!

Let's zoom in for a closer look:

[caption id="attachment_28977" align="aligncenter" width="580" caption="Shadows on the rings, closer. Credit: NASA/Cassini/UnmannedSpaceflight.com"]

[/caption] Wow! As one of the members of UnmannedSpaceflight said, "Knowledge of the rings' 3D structure is about to be revolutionized. And let's not forget that these shadow will get much longer in the coming months." Let's zoom in a little more: [caption id="attachment_28978" align="aligncenter" width="580" caption="Saturn's rings closer yet. Credit: NASA/Cassini"]

[/caption] The UnmannedSpaceflight crew has even created animations from combining several of the raw images sent back by Cassini.

In the first movie,

it doesn't look like the moonlet shadows are moving at all, but in a

more zoomed in version,

it is obvious the shadows are moving as the objects orbit around Saturn.

As Stuart Atkinson at Cumbrian Sky said,

for a long time we've speculated that Saturn's rings would look a bit like this, close up: [caption id="attachment_28979" align="aligncenter" width="260" caption="Artist concept of Saturn's rings. Image courtesy NASA/JPL/University of Colorado"]

[/caption] And now we have the first image of the ring objects, or at least the shadows they create.

Head nod to

Stuart Atkinson

for the tip, and congrats to the sharp eyes (and image editing prowess) at

UnmannedSpaceflight.com

for this amazing find! Great work!

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com