Small Moon Makes Big Waves


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!

5 Replies to “Small Moon Makes Big Waves”

  1. 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!

  2. 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?

  3. 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).

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

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

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

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