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APOD: Stereo Helene (2024 Jun 01)

Posted: Sat Jun 01, 2024 4:06 am
by APOD Robot
Image Stereo Helene

Explanation: Get out your red/blue glasses and float next to Helene, small, icy moon of Saturn. Appropriately named, Helene is a Trojan moon, so called because it orbits at a Lagrange point. A Lagrange point is a gravitationally stable position near two massive bodies, in this case Saturn and larger moon Dione. In fact, irregularly shaped ( about 36 by 32 by 30 kilometers) Helene orbits at Dione's leading Lagrange point while brotherly ice moon Polydeuces follows at Dione's trailing Lagrange point. The sharp stereo anaglyph was constructed from two Cassini images captured during a close flyby in 2011. It shows part of the Saturn-facing hemisphere of Helene mottled with craters and gully-like features.

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Re: APOD: Stereo Helene (2024 Jun 01)

Posted: Sat Jun 01, 2024 6:41 pm
by johnnydeep
Ok, can anyone explain to me why exactly it is that Helene is so "appropriate named"? I get from the links that it's something to do with John Herschel suggesting that the moons of Saturn be associated with mythical brothers and sisters of Cronus/Cronos/Kronos/Saturn; Trojan satellites and the Trojan war and Helen of Troy and that Helene is supposedly a granddaughter of Cronos and sister of Polydeuces, but why Helene particularly? I'm also having trouble pinning down an accurate genealogy of Cronos. Though this one looked promising, Helene is nowhere to be found:

Click to view full size image

Re: APOD: Stereo Helene (2024 Jun 01)

Posted: Sun Jun 02, 2024 4:30 pm
by Fred the Cat
johnnydeep wrote: Sat Jun 01, 2024 6:41 pm Ok, can anyone explain to me why exactly it is that Helene is so "appropriate named"? I get from the links that it's something to do with John Herschel suggesting that the moons of Saturn be associated with mythical brothers and sisters of Cronus/Cronos/Kronos/Saturn; Trojan satellites and the Trojan war and Helen of Troy and that Helene is supposedly a granddaughter of Cronos and sister of Polydeuces, but why Helene particularly? I'm also having trouble pinning down an accurate genealogy of Cronos. Though this one looked promising, Helene is nowhere to be found:

Hard to say but Helene may be Zeus’s Nemesis that led to a swan song. :?

That eventually morphed into one of my favorite constellations. :thumb_up: