I stumbled on this beautiful image of Saturn’s moon Rhea – and the shadow of Saturn’s rings – a few days ago. I’ve had it open in my browser ever since. In this beautiful Cassini spacecraft image, Saturn itself is in the background. The moon Rhea is gently lit in silhouette. The dark lines are a wide shadow cast by Saturn’s rings, which are seen nearly edge-on.
In this image, we’re looking toward the anti-Saturn side of Rhea – as if we were looking toward Earth from the far side of our moon. We’re looking toward the northern, sunlit side of the rings from just above the ringplane.
Rhea is 1,528 kilometers, or 949 miles, across. It’s small compared to Earth’s moon, which is 3,475 kiometers, or 2,159 miles, across.
The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on May 8, 2010. The view was obtained at a distance of approximately 2.1 million kilometers (1.3 million miles) from Rhea and at a sun-Rhea-spacecraft, or phase, angle of 101 degrees. Image scale is 13 kilometers (8 miles) per pixel.
Bottom line: Check out this great Cassini spacecraft image of Saturn’s moon Rhea in front of the backdrop of Saturn. In this image, the rings are casting a shadow on the planet.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.