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Fraser
2006-Jun-28, 07:07 PM
We're accustomed to seeing photographs of Saturn's larger moons, like Titan, Dione and Enceladus. Here's an image of one of its smallest: newly discovered Polydeuces. This moon is only 3 km (2 miles) across, and shares the same orbit as much larger Dione. Cassini took this photo on May 22, 2006 when it was approximately 73,000 kilometers (45,000 miles) away.




Read the full blog entry (http://www.universetoday.com/2006/06/28/saturns-tiny-moon-polydeuces/)

Ray Bingham
2006-Jun-29, 12:34 AM
If it "shares an orbit with Dione" is it then in a Trojan orbit? Fixed at 60 degrees ahead of or behind Dione.

Are these the only two satelites that "share an orbit"?

And why are we calling it a "Moon"? Earth has the Moon and other planets have satellites with their own names. Right?
Otherwise what is the name of earths moon?

Blob
2006-Jun-29, 12:42 AM
Hum,
it is co-orbital with Helene as well.
Helene and Polydeuces are Trojan moons, orbiting about 60 degrees ahead of and behind of Dione.

suitti
2006-Jun-29, 02:29 PM
What, if any, is the lower limit on the size of a moon? If the answer is that any dust mite is a moon, then Saturn surely has billions. Instead of buying a name for stars, perhaps we should be buying names for moons (dust mites) of Saturn. ;-}

aurora
2006-Jun-29, 03:11 PM
Earth's moon is often called Luna.

But more often, just "The Moon".

aurora
2006-Jun-29, 03:12 PM
What, if any, is the lower limit on the size of a moon? If the answer is that any dust mite is a moon, then Saturn surely has billions. Instead of buying a name for stars, perhaps we should be buying names for moons (dust mites) of Saturn. ;-}

There's a whole long thread on this topic currently.