Saturn's moons in 3-D

As the Cassini orbiter whirls past Saturn and its moons, it's racking up a growing inventory of cool imagery - including 3-D views that are worth pulling out your red-blue glasses to see.

The latest stereo views were captured late last year and released this month: The picture above shows Prometheus, a 90-mile-long (145-kilometer-long), potato-shaped "shepherd moon" that keeps Saturn's F ring in line. The gravitational influence of Prometheus sculpts the ring's inner edge, while another shepherd moon known as Pandora serves a similar function just beyond the ring's outer edge.

To create the 3-D view, Cassini's imaging team selected two black-and-white images that were taken from slightly different angles, and then processed them to add perspective when the two-tone picture is seen through red-blue glasses. The images were taken from a distance of about 35,000 miles (57,000 kilometers).

Pandora got the 3-D treatment from Cassini three and a half years ago. A full-color picture, also based on image data acquired in September 2005, shows the 50-mile-wide (81-kilometer-wide) moon in all its dull tan glory.

Saturn's water-spouting moon, Enceladus, is featured in another 3-D image that was released this week. Cassini took lots of pictures during a fly-by of Enceladus last November, and this week's release highlighted a region called Baghdad Sulcus. The region is right in the middle of a series of fissures known as "tiger stripes," so named because they slash through the moon's south polar region like the markings on a big cat.

Cassini has documented clear evidence that icy particles, water vapor and organic compounds are spraying out into space from geysers in the tiger stripes. That leads scientists to suspect that there's liquid water and perhaps even life lurking beneath Enceladus' icy shell. The latest 3-D imagery, acquired from a distance of 1,200 miles (2,000 kilometers), highlights the rugged peaks and faults of Baghdad Sulcus. 

These images merely scratch the surface of Cassini's 3-D goodness. Check out these red-blue blasts from the past:

• Hyperion: This moon looks like a space sponge, measuring 204 miles (328 kilometers) in its widest dimension.
• Iapetus: Saturn's two-tone moon has had many turns in the 3-D spotlight. MarsUnearthed shows you the whole disk as well as several views of Iapetus' crateredsurface, all courtesy of Cassini. The spacecraft also caught sight of Iapetus' towering peaks. 
• Dione: This icy moon looks like a giant marble floating in space, especially when you see it with 3-D glasses.
• Phoebe: Cassini's image of Saturn's far-out moon really pops in 3-D, and here's a closer view of its craters.
• Rhea: Get a look at 3-D craters on Saturn's second-largest moon.

If you're having a hard time finding the red-blue glasses required for the 3-D effect, you can turn to the vendors listed on this NASA Web page. In something of a science outreach experiment, I made my own contribution to the cause today by sending out 40 sets of cardboard glasses that were provided by Microsoft Research's WorldWide Telescope team. (Msnbc.com is a Microsoft-NBC Universal joint venture.)

Even if you're not into 3-D pictures, there are plenty of 2-D wonders to choose from. If it's Cassini imagery you're looking for, check out NASA's Saturn Web site as well as the Cassini imaging team's Internet home base.

For a wide-angle view of the cosmos, click through our latest "Month in Space" slideshow. Here are links to more information and bigger pictures about the slideshow images:

• Hangin' out in outer space: Spacewalker at work.
• Look! Up in the sky! WISE's view of a comet.
• Space Snowmageddon: Satellite view of storm.
• Storms on the sun: STEREO catches solar flare.
• X marks the spot: Aftermath of asteroid collision?
• Our home in space: Beauty shot of space station.
• Martian chocolate: The latest treat from Opportunity rover.
• Nature's fireworks: Big picture of aurora over Norway.
• Craters young and old: Wide view from Mars Express.
• Shuttle on the horizon: Endeavour's must-see silhouette.
• Mojave on Mars: Orbiter spots blocks of bedrock.
• Starry night: Enjoy a star-forming nebula's scenery.
• Cosmic potato: Another view of Prometheus.
• Oh, Orion! High-resolution view of famous nebula.
• Heading into space:Night launch for Endeavour.
• Light shows on Saturn: Hubble spots Saturnian storms.
• Farewell to the shuttle: Endeavour pulls away from station.
• Space history in Siberia: Museum features Russian rockets.
• Falcon rising: SpaceX's rocket takes its place on the pad.
• The galaxy next door: Andromeda, as seen by WISE.
• Twin eruptions: Volcanoes act up on Kamchatka Peninsula.
• Outside looking in: Parting shot from new space lookout.

More about 3-D imagery:

• Space in 3-D
• Mars in 3-D
• More 3-D delights from Mars
• Souped-up views from the Red Planet
• Rover sends 3-D view from crater's rim
• Lights, camera ... Hubble 3D! | Opening soon

Update for 10:27 p.m. ET: When this item was first posted, I put out an offer to mail out cardboard 3-D glasses to the first 40 people who sent me e-mails. All those have now been spoken for - but if I get more from Microsoft Research, you'll be the first to know. Thanks so much to all who wrote in. The specs are in the mail.

Join the Cosmic Log corps by signing up as my Facebook friend or hooking up on Twitter. And if you really want to be friendly, ask me about "The Case for Pluto." I'll be visiting the Eastern Iowa Observatory and Learning Center on March 6 to talk about "The Case" and the planet quest. If you're in the area, stop by and say hello.