Small Moon Makes Big Waves

by Nancy Atkinson on July 6, 2010

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A Cassini image of the moon Daphnis making waves in Saturn's rings. Credit: NASA/JPL/Space Science Institute

Saturn’s moon Daphnis is only 8 kilometers wide, but it has a fairly substantial effect on the A ring, making waves on the ring’s edge. According to Carolyn Porco on Twitter, this is the closest look yet at this mini, moving moon. Daphnis resides in the Keeler Gap, which is about 42 km wide, but the moon’s eccentric orbit causes its distance from Saturn to vary by almost 9 km, and its inclination causes it to move up and down by about 17 km. That may not sound like much, but within a small gap, this variability causes the waves seen in the edges of the gap. We’ve only known about Daphnis’ existence since 2005, one of the many discoveries made by the Cassini spacecraft, and this is the first image where Daphnis is more than just a little dot. Click on the image to get a closer look.

This image is hot off the presses, as it was taken on July 5, 2010, and sent to Earth just yesterday (July 6). See below for a great new look at Saturn’s ring.


New raw image of Saturn's rings. Credit: NASA/JPL/Space Science Institute

Click the image for a larger version, and prepare to be wowed!

Source: CICLOPS, with a hat tip to Stu Atkinson!

About

Nancy Atkinson is Universe Today's Senior Editor. She also is the host of the NASA Lunar Science Institute podcast and works with the Astronomy Cast and 365 Days of Astronomy podcasts. Nancy is also a NASA/JPL Solar System Ambassador.

  • http://home.comcast.net/~jacobsdale/AquaFarmIN.pps Aqua

    Nice~ Saturn is SOOO awesome! Still nearly edge on at present it is a fine view anyway and always worth checking out in practically any telescope! These images are jaw dropping.. Cassini rocks! Now, if only a small asteroid or comet would plunge through the rings and smack into the surface of Saturn… THAT would really way double extra groovy cool, especially if Cassini saw it happening!

  • Jon Hanford

    At first glance I thought Daphnis looked somewhat similar to Phobos (though they of course differ greatly in composition). A quick check shows that the moon is roughly half the diameter of Phobos or Deimos. That sort of gives me *some* sense of scale. Still, it’s just a mote in the vastness of Saturn’s ring system.

    I wonder what Keeler would make of all this?

  • IVAN3MAN_AT_LARGE

    This image is hot off the presses, as it was taken on July 5, 2010, and sent to Earth [1,460,000,000 km away] just yesterday (July 6).

    [Rant]
    However, it still takes the bloody bureaucrat banks, here in the U.K., 3-4 days to clear a friggin’ cheque!
    [/Rant]

  • IVAN3MAN_AT_LARGE

    P.S. Actually, the correct term should be bureaucratic, but you all know what I mean!

  • Torbjorn Larsson OM

    IVAN3MAN_AT_LARGE, I’m sorry but that bureao … bureac …, I’m going blind somewhere there. Too boring/scary?

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