Help understanding this unsettling image of Titan, Epimetheus, and Saturn's rings?

  • The NY Times article Saturn’s Rings Are Sculpted by a Crew of Mini-Moons is really interesting and links to the recent paywalled paper in Science Close Cassini flybys of Saturn’s ring moons Pan, Daphnis, Atlas, Pandora, and Epimetheus

    But I absolutely can't understand one of the photos in the NY Times article, shown below. Titan seems to be...

    1. behind Saturn's rings, and yet it is

    2. huge relative the spacing of the rings, and yet it

    3. appears to be out of focus while the rings and Epimetheus are in focus.

    Can someone help me understand how all of these can be true at the same time?

    In the foreground, the moon Epimetheus appearing to hover above Saturn's rings. Epimetheus is dwarfed by Titan in the background.CreditNASA/JPL/Space Science Institute

    Epimetheus, Titan and Saturn's Rings

    Epimetheus, Titan and Saturn's Rings cropped

    Something that might contribute to this illusion is the extremely narrow angle used. I know Titan is much farther away than the rings, so I intuitively expect it to look much smaller than it is, so it looks enormous in this picture. Because the focal length of the camera is so high, Titan isn't actually that much bigger than it appears.

    @DarthFennec yes, the 2nd link in this comment shows that the FOV for this photo is only about 0.35 degrees.

    How are the rings so thin if the moons appear to have vastly different inclinations? That's what looks strange to me.

    Beautiful, stunning image. In case you haven't seen it I would like to recommend Carolyn Porco's classic TED talk about Cassini. It's well worth watching; she puts things in perspective ;-).

  • Mike G

    Mike G Correct answer

    3 years ago

    The JPL Solar System Simulator doesn't show Epimetheus but does show Titan behind the Encke gap at 2006-04-28 08:12 UTC.

    Titan at 08:12, narrow field

    The simulated surface texture is probably composed of
    VIMS images
    in infrared wavelengths where Titan's atmosphere is relatively transparent.
    On the real Titan, haze scatters visible light so strongly that the surface is indistinct and the edge looks fuzzy.

    If we zoom out, we see that we are looking near the outer edge of the rings at a very shallow angle.
    This is why they cover less than half of Titan's 10-arcminute apparent diameter.

    Since Epimetheus appears above the rings while we are looking from below, it must be in front of them.

    Titan at 08:12, wide field

    Simulated images courtesy NASA/JPL-Caltech

    Wow I had no idea that JPL had such a Solar System Simulator website. These are quit helpful, thanks!

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