Strange New Objects Seen In Saturn's Rings 113
Every 15 Earth years, Saturn has its equinox — the time during which its rotational axis is perpendicular to the rays from the sun, so that the sun is always directly "overhead" of Saturn's equator. This is significant because Saturn's rings orbit over the equator, so during the equinox, light from the sun hits them edge-on. This means that any objects wider than the rings, or orbiting above or below them, cast long shadows and are much easier to see. For the first time, we're able to get detailed images of these objects, thanks to Cassini. A moonlet, perhaps 1,300 feet in diameter, has been discovered in the B-ring, and the Bad Astronomy blog points out another object that seems to be bursting through the F-ring. Quoting: "The upward-angled structure is definitely real, as witnessed by the shadow it's casting on the ring material to the lower left. And what's with the bright patch right where this object seems to have slammed into the rings? Did it shatter millions of icy particles, revealing their shinier interior material, making them brighter? Clearly, something awesome and amazing happened here.
Re:F-Ring? (Score:1, Informative)
Except it.. uh... does [nasa.gov].
Re:radial distance? (Score:5, Informative)
Re:Savages (Score:3, Informative)
Re:That's no moon (Score:3, Informative)
In the original novel, the monolith was on a moon of Saturn.
Re:Obligatory Footfall (Score:3, Informative)
Here you go. [si.edu]
Re:radial distance? (Score:4, Informative)
According to Ciclops [ciclops.org] it's 480 km inward of the outer edge of the B ring, which puts it at a radial distance of 117,100 km
Thanks very much; that's a much better source of information than TFA.
Re:That's no moon (Score:5, Informative)
Re:radial distance? (Score:4, Informative)
We assume an orientation of the anomaly parallel to Saturn's axis, but from the brightness of the reflected light on the "dark side" of it suggests an angle maybe closer to that of the ring plane... remember where the sun is. Although, it could be illumination of backscatter from Saturn, or by internal reflections between the particles.
Ring particles could be caused to move by electrostatics, not just gravity or collision, so I'm thinking a long plasma trail behind a comet passing thru, or a slower moving (orbital?) charged object causing a ruction. Heck, why not a moving cloud of magnetic particles colliding with the ring bits, which are then drawn along Saturns magnetic field.
Re:That's no moon (Score:3, Informative)
Re:That's no moon (Score:5, Informative)
Re:radial distance? (Score:4, Informative)
Actually, no. Gravity WILL, in effect, pull objects apart thanks to tides. This is what keeps the rings from accreting into a single body, more or less. So gravity, while most simply an attractive force, *can* actual cause repulsion. (Another fine example is the F ring itself, which is shepherded by two moons. The moons push the ring back when it tries to spread toward the moons.)
This is what keeps the rings from accreting, more or less. And collisions are so slow that grinding isn't a *huge* factor, although some amount of re-collection of dust onto macroscopic particles probably helps that significantly.
Re:radial distance? (Score:4, Informative)
No, while I haven't read the papers either, I can confirm that gravity will not be the force pulling objects apart, at least not directly, as it is an attractive force.
Maybe you should do some reading. Start with googling "roche limit". Tidal forces ripping an object apart are how the rings got formed in the first place.
Re:That's no moon (Score:3, Informative)
In the original novel, the monolith was on a moon of Saturn.
Too bad the movie came first.
The movie was originally shot to finish at Saturn but Kubrick changed his mind. The Saturn footage was recycled for Silent Running.