Enceladus fires on Alderaan

Bad Astronomy
By Phil Plait
Nov 8, 2011 5:50 PMNov 20, 2019 1:07 AM

Newsletter

Sign up for our email newsletter for the latest science news
 

After 7+ years of orbiting Saturn, the Cassini spacecraft is still knockin' 'em out of the park. On October 19 it swung by the icy moon Enceladus, taking dozens of amazing images of the little world. When it was 65,000 km (40,000 miles) away, it took this shot, right out of Star Wars:

[Click to DeathStarenate.] That's not a laser blasting out from the moon; it's actually Saturn's rings seen in the background! At the moment this was taken, Cassini was nearly in the same plane as the huge ring system circling Saturn, and so they're seen edge-on, looking like a bright line. The Sun is off to the right, illuminating Enceladus, which from this angle makes it a lovely crescent. Normally, Enceladus looks really bright since its surface is icy and very reflective, but in this case the short exposure downplays its shininess.

The rings, though, are made of small particles, and when illuminated tend to throw that light forward (much like a wet road surface reflects oncoming headlights very strongly toward you). The sunlight scatters off the rings and gets bounced at the camera, making them look very bright. As Cassini orbits Saturn its position relative to the moons and rings changes, and so within a short period of time of the show above it got this one, inset here, where the geometry is slightly different. I think we're looking up from underneath the rings, so the bottom line is the far side of the rings, the upper line the near side, and then Enceladus. Both arcs and the moon are in the same plane, so if you picture it this is the only way this lineup makes sense! This image also shows a different view. I found those images going through the Cassini raw images archive. I found something else, too... but that'll have to wait for the next post. Stay Tuned! Image Credit: NASA/JPL/Space Science Institute


Related posts: - Watch out, Titan! Vader’s onto you! - Midnight on a ringed world - Enceladus on full afterburner - Enceladus sprays anew! - Saturn weather forecast: rings, with light rain from Enceladus

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!

Subscribe

Already a subscriber?

Register or Log In

More From Discover
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2025 LabX Media Group