![]() “And that energy can create under-ice oceans, maybe even habitable zones. “The same gravity that causes all these weird phenomena that we’re seeing on these little moons causes energy to be pumped into some of the larger ones,” says Terrile. Understanding Pan and Atlas may be key to understanding gravity’s role in all of Saturn’s moons. “It may also be some kind of gravitational tidal effect from being near all this ring material,” says Terrile. The dominant theory for how the ridges form is that because the moons’ diameters are so much larger than the ring’s thickness, they gather material along their equators as they plow through stray ring particles. The two moons are approximately the same size, but Pan is embedded within a ring, and Atlas is along the outer edge. “What is especially interesting is the extent to which the soft material seems to bury and mute any crisp-looking topographic features even on the central ‘core’ structure,” says Paul Helfenstein at Cornell University in Ithaca, New York, who helped plan the flyby.Īnother moon, Pan, also has an equatorial ridge, but another recent flyby showed its ridge is rough with tension cracks and craters. “It looks like it’s covered in some kind of fluffy material.” “It looks more subdued than I expected,” Terrile says. We already knew Atlas has a UFO-like ridge around its equator, but surprisingly, the new images show that ridge is smooth. “This is a really interesting kind of dynamical dance that these moons do with the ring particles.” But instead, the ring’s shape is held by two other moons, Janus and Epimetheus. “At the time, we thought the satellite was holding out the edge of the A ring,” Terrile says. But Atlas appears to be a shepherd moon that isn’t responsible for shepherding ring particles. My immediate hunch was that it might be associated with the orbit of one of Saturn's moons and after some calculation I identified Atlas as the prime suspect.Some of Saturn’s moons, called shepherd moons, use their gravity to keep the planet’s famous rings in check. "It was while studying the F-ring in these images that I discovered the faint ring of material. "The role of the moons in this region was a mystery," he said. It is sometimes described as having the appearance of a ravioli. ![]() It is a small, walnut-shaped moon approximately 35 kilometres across and 23 km wide that orbits within the Encke Gap in Saturns A Ring.Pan is a ring shepherd and is responsible for keeping the Encke Gap free of ring particles. He also may have discovered yet another ring, 138,000 kms from the centre, linked to Saturn's moon Atlas. Pan is the innermost named moon of Saturn. ![]() But we have to be careful: the F ring is notorious for producing bizarre phenomena." "In any other ring system, in any other planet, this would be classified as a satellite, a new moon. American colleagues found the object again five hours later: however, this time it was in an unexpected place. He and colleagues are now trying to calculate the object's orbit. There is certainly something there that has to be explained." I would like to say they are moons but we do not actually know yet. The discovery is of at least one and possibly two objects. "It was an incredible privilege to be the first person to spot it. "I noticed this barely detectable object skirting the outer part of the F ring," he said.
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