Perhaps foolishly emboldened by the success of our model of self-gravity wakes (aligned clumps of particles) in Saturn’s rings in predicting our last observation of Saturn’s A ring, I have applied our model of Saturn’s B ring to our next observation and made a prediction about what we’ll see there. The B ring is the largest planetary ring in the solar system, and it is the big bright one in the middle in pictures of Saturn’s rings. Here’s a nice example. The B ring is particularly intriguing because, unlike the A ring where there are a lot of structures that we have some explanation for, the B ring is dominated by grooves and valleys and peaks in particle packing that are unexplained. The central part of the B ring seems to be totally opaque, so it is hiding its secrets from the stellar occultation measurements I study (where we observe the flickering of light of a star through the rings). But the inner and outer parts of the B ring allow a little light through, and we were able to piece our first observations from Cassini together to identify the signature of the same parallel clumps of particles that are prominent in the A ring. The B ring work has not yet been published, so it is with some trepidation that I present these predictions of our next measurement of the B ring.
Because the B ring is so large, I’ve broken it into two parts, and left out the central opaque region where we can make no prediction (except that it will also be opaque). The diamonds show my prediction for the next measurement on September 9, 2006. The values shown in these graphs are optical depths, which is a measure of how opaque or transparent something appears. The curious thing about Saturn’s rings that I’m seeing in these studies is the transparency of the rings depends on the angle you look at them. So I’m predicting that the new measurement will show the B ring to have a relatively low optical depth (be more transparent). The other curves show some of the previous observations to give an idea of the range of possible values. The prediction curve is not continuous because we did not have enough good data to fit the model to it all the way across the ring. Here are the predictions. Check back the week of September 11 to see how I did.
