The Cassini spacecraft has detected two and possibly three new additions to the already full environment of Saturn, and scientists are puzzled over what they've seen.
The first discovery is a wispy arc of ice and rocky material that sits between the A and F rings. The second is a tiny object skirting the outer edge of the F ring, which may be a moon but could just be a clump of rubble, scientists said this week. A third object is even more enigmatic.
At a distance of 86,000 miles (138,000 kilometers) from the center of Saturn, the previously unknown ring, designated S/2004 1R, lies in the orbit of the small moon Atlas. It is unknown yet whether the ring actually makes a full circle around the planet or is just an arc.
Astronomers have estimated the width of material in the ring to be 190 miles (300 kilometers). In comparison, the A ring is 9,070 miles (14,600 kilometers) wide, while the F ring is 31 miles (50 kilometers) wide.
The ring system begins from the inside out in this order: D, C, B, A, F, G, E.
The other discovery is an object, temporarily called S/2004 S3, which is estimated to be 2 to 3 miles (4 to 5 kilometers) across. It orbits Saturn at a distance of approximately 86,420 miles (141,000 kilometers) from the center of the planet, which places it about 600 miles (1,000 kilometers) outside of the F ring.
The resolution is not yet good enough to determine the exact nature of the newfound object. If it turns out to be a solid body, it would be the 34th satellite around Saturn. Earlier this summer, NASA announced the discovery of two Saturn moons, S/2004 S1 and S/2004 S2, which are of similar size to S/2004 S3.
Carl Murray, Cassini imaging team member from Queen Mary College, University of London, was the first to notice the new astronomical entities. The possible moon showed up in a series of images taken on June 21, while the ring was spotted in a wide-angle shot from July 1. During this time period, the spacecraft was in the midst of establishing orbit around Saturn.
Another object -- possibly another moon -- was also detected.
When Joseph Spitale, a planetary scientist at the Space Science Institute in Boulder, Colo., looked over the images involvoing S/2004 S3, "I found that about five hours after first being sighted, it seemed to be orbiting interior to the F ring," he said. "If this is the same object then it has an orbit that crosses the F ring, which makes it a strange object."
The dynamics of an object crossing the ring are puzzling, scientists say. For now, the inner object sighted by Spitale is considered a separate object with the temporary designation S/2004 S 4. S4 is roughly the same size as S3.
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Michael Schirber is a freelance writer based in Lyons, France who began writing for Space.com and Live Science in 2004 . He's covered a wide range of topics for Space.com and Live Science, from the origin of life to the physics of NASCAR driving. He also authored a long series of articles about environmental technology. Michael earned a Ph.D. in astrophysics from Ohio State University while studying quasars and the ultraviolet background. Over the years, Michael has also written for Science, Physics World, and New Scientist, most recently as a corresponding editor for Physics.