Blogs / Bad Astronomy

Just a quick note: Emily, at The Planetary Society Blog, just posted a way cool mosaic made up of four pictures from Cassini showing the Enceladus icescape. I love the perspective on it, and how you can tell you’re looking down on the tiny moon from an oblique angle. It’s quite lovely. Go look!

And in case you missed it, here are links to 3D red/green anaglyphs of Enceladus too. Awesome.

On November 20, 2009, the Cassini spacecraft buzzed the surface of Saturn’s icy moon Enceladus once again, returning dramatic images of its water geysers and wrinkled, ridged surface:

That raw image (which means it has not been processed to remove instrument/detector artifacts like bad pixels and such) was taken when Cassini was a mere 2000 km (1200 miles) above the moon’s surface. The features are beautiful and plentiful… and it looks like a great place to ski. Bonus: the low gravity would make the experience last longer!

Cassini got an overview of the geysers, too, when it was still more than 500,000 km away:

Remember, these are raw images; that bright "star" just above Enceladus is probably a cosmic ray hit on the detector and not an actual astronomical object.

Over at The Planetary Society blog Emily is, of course, having kittens over the pictures, and has made some stereoscopic pairs of them (though I’ll wait for the red/green anaglyphs; crossing my eyes at my monitor makes my tummy queasy). [Edited to add: in the comments below, BABloggee Alex links to anaglyphs he created. Very cool!]

Stay tuned, because as these images are processed things will only get cooler.

Today (as I write this), the Cassini spacecraft passed just a hair under 100 km (62 miles) from the surface of Enceladus, an icy moon of Saturn. This little moon is scientifically incredibly interesting; there are geysers at the south pole that are spewing out water! The images are just now coming in, and have not been calibrated or processed yet, but they are still breathtaking. I particularly like this one:

[Click to embiggen, as usual.]

That, me droogs, is high art. Enceladus was about 190,000 km (118,000 miles) away from Cassini when that shot was taken, a little under half the distance of the Earth to the Moon. From this angle, Enceladus is lit in a gorgeous thin crescent, but we can see detail on the dark side, I suspect due to light reflecting off Saturn onto the moon. You can see ridges in the surface; the moon has a thick crust of ice presumably floating on an undersurface ocean of water (though there have been arguments about that), so the surface is a bit of a mess, looking for all the world(s) like ice floes seen at our own north pole.

The geysers are obvious too, blasts of light at the top of the moon’s limb as the water erupting from the south pole is lit by the Sun. Thumbing through the raw images is a delight (once there, set the target for Enceladus, choose both narrow and wide angle, and put in dates of October 30 through November 3 to narrow the search). You’ll see dramatic images of the moon, its limb, the geysers, and everything.

Stunning, and wondrous. And there’s better to come: as Carolyn Porco herself mentions on Twitter, the primary purpose of this flyby was not to get images; November 21st is the imaging flyby where we’ll see lots of spectacular shots of the moon. So stay tuned!

Image credit: NASA/JPL/Space Science Institute