Cassini buzzes Enceladus once again

By Phil Plait | November 21, 2009 11:29 am

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.

CATEGORIZED UNDER: Astronomy, Pretty pictures, Space
MORE ABOUT: Cassini, Enceladus, Saturn

Comments (25)

Links to this Post

  1. Cassini buzzes Enceladus once again « New Skeptic | November 22, 2009
  1. earth2allie

    How often do you think cosmic rays hit the detector? Seems either pretty unlikely, or there are a lot of cosmic rays out there.

    I love it when @elakdawalla has kittens over pictures. We all get to have kittens then, and really, who doesn’t like kittens? I have a hell of a headache from crossing my eyes for the past hour, but they are super cool in 3D!

  2. It really does look like snow, but obviously it can’t be! Still…

  3. CRs hit detectors all the time. It’s a major problem when dealing with space-based imagery. Do a search of my website for more info. :)

  4. kevbo

    I built my own old-fashioned stereoscope for taking my own 3D pictures (just lock your camera’s exposure/focus settings – most digital cameras can do this in ‘stitch’ or ‘panorama’ mode). Coolness it works for these pics perfectly. It also works for colour pictures, which red/green analglyphs don’t support.

    Heh heh… I said “Analglyph”…

    Google ‘stereoscope’ for tons of resources, including lenses if you wanna make your own.

  5. Way back, when I used to be outside stargazing most every night, I would notice cosmic ray hits in my own eyes all the time. Seriously. They’re not that rare. If you ever see a tiny blip of greenish light, apparently superimposed on whatever it is you’re looking at, that’s probably a cosmic ray triggering a light receptor in your retina.

  6. Pareidolius

    The stereo images of the geysers on the limb is worth the nausea. Every primate hair on my primate body stood on end when that slipped into stereo. Lucky, lucky, lucky to be alive at this time in history.
    And this, Kevbo, (*) is an actual analglyph.

  7. Alex

    Very cool. I don’t have a pair of stereo glasses on-hand to check these, but I threw the first image together as a red/green anaglyph. One has the stereo pair backwards for the “standard” glasses layout, but like I said I can’t currently check to see which one. Let me know if these work!

    [EDIT] I put the second one together as well.

  8. NewEnglandBob

    I thought the ‘bright star’ was my bad pixel on the display until I scrolled. My bad pixel is halfway between the ‘bright star’ and the geyser.

  9. Sili

    It’s not just in space. I used to do crystallography, and after we got to use CCDs for that, we saw CRs all the time.

  10. Torbjörn Larsson, OM

    But, but, this is 121 EN …, what’s the word on the earlier flyby (120 EN)? That would be loaded with goodies on the particles and gases we see here.

    Sniff, no actual particle data… I’m almost exclusively visually processing input, but this’s [sic, according to my spell checker] not fair, I’ll tell ya.

  11. Rob

    Nice pictures, especially Enceladus; so far away but we’ve got a robot taking pics from right up close. How long before Richard Hoagland zooms in on Enceladus and finds The Handiwork of Alien Civilisation there, too?

  12. Q

    How do you sort out “real” pixels from artifacts?

  13. llewelly

    Rob, the aliens have been too busy building the Great Wall of Iapetus to screw around on Enceladus.

  14. llewelly

    How do you sort out “real” pixels from artifacts?

    If the same object appears in multiple pictures, it’s not a cosmic ray.
    If the same pixel is the same color in multiple pictures taken from different vantage points, it’s probably a bad pixel (as in a hardware problem).
    I would imagine there is a long list of similar heuristics by which artifacts of various sorts can be eliminated with useful confidence. But do note eliminating artifacts with 100% confidence is not possible.

  15. JigsawMan

    Clearly I have not been paying proper attention to the state of the art of astronomy. I am utterly blown away that that first image was taken 200 miles above the surface of Enceladus YESTERDAY and today is on the internets for the world to see. Even raw data, I consider that pretty impressive.

  16. Michael Kingsford Gray

    Thanks, Alex!
    Those anaglyphs are truly breathtaking.

  17. Daniel J. Andrews

    Phil…you don’t need to cross your eyes to see 3-D pics. It does work but will give you an opposite image (e.g. a hole in the ground becomes a hill on the ground). What you need to do is look past the screen. You actually do this when you are tired anyway. If paragraphs and words double then you’d probably see a picture in 3-D if there was one on the screen.

    The way I learned was to hold one of the magic eye pictures right up to my nose, let me eyes just relax, then slowly pull the picture away. Very slowly. Don’t try to focus on the picture, just relax. At some point you’ll start to see something, focus on it….and lose it. So start over again. Soon you’ll be able to hold the 3-D image quite easily and move your eyes around and focus on it all without losing the image itself.

    It can be a useful skill to have depending on your profession and I use it on air photos, organic chemistry molecules in textbooks (I scoff at the 3D glasses–I don’t need no steenkin’ glasses), and of course, for these astronomy pictures. Check online for better instructions on how to do it.

  18. Jeremy


    CR’s hit even ground-based detectors all the time. I can hardly take a 5 minute exposure without picking up a few.

  19. Plutonium being from Pluto

    Enceladus a small and icy moon

    With geysers active such a boon

    It’s tiger stripes they burn so bright

    For such a moon so small

    It is a wonder of our system

    Saturn’s glistening jewel!

    – Stevo R / Plutonium being from Pluto

    (Just a bit of doggrel to commemorate the occasion. Hope y’all enjoy it.)

  20. StevoR

    Thinking things Saturn~wise, if you haven’t already seen it then this is well worth checking out :

    Thanks to Gary Ansorge who posted this earlier on another thread here. :-)

    PS. Sorry if this is a double post. Tried to send just now & it didn’t seem to work, no “awaiting moderation” message or anything – just nothing.

  21. Plutonium being from Pluto

    Hmm .. My latest post (NOT the doggrel one, 19, above but another with link on “if Saturn’s rings going around Earth” instead) is not appearing here & nor is any awaiting moderation” message. Tried posting a while ago & refreshing and coming back but still no joy. It is saying ‘duplicate comment detected’ but it ain’t turning up! What’s going on? :-(

  22. Don Gisselbeck

    More skiing terrain than we’ve got here on earth. That is important since skiing was the main reason for creating the universe (unless it was to produce Bach). It looks very steep in the stereo images.

  23. Blizno

    “That is important since skiing was the main reason for creating the universe (unless it was to produce Bach).”

    What, are you questioning Bachism? It is obvious to all that Bach is the only reason for Mithras to have Created the universe. No sane person could ever doubt Bachism. Come ON!


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