Sarurn moon atlas pancake8/1/2023 ![]() ![]() Credit: NASA/JPL-Caltech/Space Science Instituteįigure 2. (The Daphnis image in Figure 1 was colored using the same green filter image for all three color channels, adjusted to have a realistic appearance next to the other two moons.) A version of the montage using only monochrome images is also provided (Figure 2). Images of Atlas and Pan taken using infrared, green and ultraviolet spectral filters were combined to create enhanced-color views (Figure 1), which highlight subtle color differences across the moons' surfaces at wavelengths not visible to human eyes. Pan's equatorial band is much thinner and more sharply defined, and the central mass of Atlas (the part underneath the smooth equatorial band) appears to be smaller than that of Pan. Two differences between Atlas and Pan are obvious in this montage. This montage of views from NASA's Cassini spacecraft shows three of Saturn's small ring moons: Atlas, Daphnis and Pan at the same scale for ease of comparison. The question gnawing at astronomers is to figure out how old the rings are.Ī study published in January, based on Cassini data, concluded that they were relatively young-somewhere between 100 million and one billion years old.įigure 1. "It's all in flux, science driven by disagreements," she said. The rings and moons depicted are not to scale. This graphic shows the ring moons inspected by NASA's Cassini spacecraft in super-close flybys. The study published on Thursday is only one preview of the discoveries yet to come. The data captured by Cassini's instruments are still being assessed. "I want to work for at least another decade on this stuff," Bonnie Buratti, a planetary astronomer at the US space agency's Jet Propulsion Laboratory in California, told AFP. Some 4,000 scientific articles have been published about Cassini's findings, and the well of knowledge is nowhere near dry. In its final year of operation, it inserted itself between the rings, sending data back to Earth until it went dark on September 13, 2017, 20 years after its launch. They are wedged in the gaps separating the planet's rings. They are either round, shaped like flying saucers or resemble potatoes. Pan, Daphnis, Atlas, Pandora and Epimetheus each measure between eight and 116 kilometers (five to 72 miles) in diameter. ![]() doi: 10.1016/j.icarus.2010.01.025.On Thursday, for the first time, astronomers and scientists are detailing their findings about the moons in the US journal Science. "Sizes, shapes, and derived properties of the saturnian satellites after the Cassini nominal mission" (PDF). "The orbits of Saturn's small satellites derived from combined historic and Cassini imaging observations". "Satellites of Jupiter and Saturn" (naming the moon). Archived from the original (discovery) on. (Subscription or participating institution membership required.) Because the orbits of Prometheus and Pandora are chaotic, it is suspected that Atlas's may be as well. ![]() Ītlas is significantly perturbed by Prometheus and to a lesser degree by Pandora, leading to excursions in longitude of up to 600 km (~0.25°) away from the precessing Keplerian orbit with a rough period of about 3 years. This would mean that for any additional particles impacting the equator, the centrifugal force will nearly overcome Atlas's tiny gravity, and they will probably be lost. In fact, the size of the equatorial ridge is comparable with the expected Roche lobe of the moon. The most likely explanation for this unusual and prominent structure is that ring material swept up by the moon accumulates on the moon, with a strong preference for the equator due to the ring's thinness. High-resolution images taken in June 2005 by Cassini revealed Atlas to have a roughly spherical centre surrounded by a large, smooth equatorial ridge. In 2004 a faint, thin ring, temporarily designated R/2004 S 1, was discovered in the Atlantean orbit. However, now it is known that the outer edge of the ring is instead maintained by a 7:6 orbital resonance with the larger but more distant moons Janus and Epimetheus. It is also designated Saturn XV.Ītlas is the closest satellite to the sharp outer edge of the A ring, and was long thought to be a shepherd satellite for this ring. In 1983 it was officially named after Atlas of Greek mythology, because it "holds the rings on its shoulders" like the Titan Atlas held the sky up above the Earth. Atlas is an inner satellite of Saturn which was discovered by Richard Terrile in 1980 from Voyager photos and was designated S/1980 S 28. ![]()
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