Cool Cassini animations
Posted by Emily Lakdawalla
31-10-2007 17:43 CDT
There have been some tremendous sets of images posted to the Cassini raw images website lately, and Gordan Ugarkovic has stepped in to animate them.
This first one absolutely took my breath away. It is an animation consisting of 254 different frames on one edge of Saturn's rings (3.4 MB, Quicktime .mov format). Gordan has posted it at 12 frames per second, and even at that rate it runs 21 seconds long. As you watch, you see seven of Saturn's moons spin around the ring ansa. Watch it again and you'll notice the little waves excited in the ring edges by the passage of these moons, and you'll see the braiding of the F ring. Watch it again and you'll observe that some rings are more eccentric than others. I'm sorry I can't post a preview, but it would be impossible to make one with a small enough file size that would do the sequence justice. To all of you who ever give talks, formal or informal, on space exploration, download this movie and show it off. It does an amazing job of capturing the dynamism of Saturn's ring system.
The first three moons that pop into view, almost at the same time, are Pandora (outside the skinny F ring), Prometheus (inside the F ring), and Atlas (outside the A ring). If I'm not mistaken, I think that maybe Daphnis is also running in the same pack in its tiny gap, the Keeler gap, at the outermost edge of the A ring. As Prometheus passes by you can see the gores left behind in the F ring by its periodic "collision" with the ring. Janus pops into view next. After that one disappears, you can start to see a bunch of brighter ringlets in the largest visible gap in the image, which is the Encke gap, home to Pan. After Janus reappears, Pan pops into view in the gap, right behind a double ringlet. Right at the end, Epimetheus hoves into view at the upper edge. After you've had fun watching the moons a few times, ignore the moons and watch all the wave action and eccentricity in the rings. It's absolutely mesmerizing.
I just realized that I forgot to post this amazing animation of Prometheus making one of those gores; this one was released by the imaging team a few weeks ago on the occasion of Cassini's 10th anniversary in space.The other animation that Gordan produced from recently released images is this absolutely lovely one of Mimas "rising" from behind Saturn. I put "rising" in quotes because Gordan has rotated the view so that north is to the right, for artistic effect; but it's a nice effect! The animation's color is somewhat true; the entire animation has been colored based upon color frames taken along with the last image in the animation.
I'll also mention that I have finally received an updated version of the tour table encompassing the entire extended mission. It's going to take me a little while to process it and update that page, but I'll get it out soon. Before I embark on that project, if anybody has any suggestions for improvements to that page, now would be the time to make them...I think I'm going to add an entry for orbit inclination and phase to the Saturn periapsis and apoapsis entries, as that tells you a lot about what Cassini will be seeing on each orbit.
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