APOD: Stereo Helene (2019 Jun 15)

[APOD Robot]

Stereo Helene

Explanation: Get out your red/blue glasses and float next to Helene, small, icy moon of Saturn. Appropriately named, Helene is one of four known Trojan moons, 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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[BDanielMayfield]

I note the features that look like gullies are called "gully-like" in the explanation. Is gravity too weak on a body this small to carve erosional gullies?

P.S. That wasn't meant to be critical of the explanation's wording. Just seeking info.

Bruce

[orin stepanek]

Nicely done stereo; it loos like the head of some kind of animal! Is it pure ice?

[Chris Peterson]

Nicely done stereo; it loos like the head of some kind of animal! :D Is it pure ice?

Define "ice". Define "pure".

[Boomer12k]

Really good 3D effect for me. This is one of the very few that actually APPEAR to bring out the objects from my monitor. Like about 6 inches...especially on the left side.

I wonder what the striations sweeping through some areas are... grooves from ice evaporation? There are places that look like "water pathways", and such... really puzzling to me... solar wind? Some are really long, or is it just "rough terrain"?

Really good work...

:---[===] *

[Boomer12k]

Nicely done stereo; it loos like the head of some kind of animal! Is it pure ice?

I don't think it is "pure ice", but ice and rocky mix...

:---[===] *

[orin stepanek]

Nicely done stereo; it loos like the head of some kind of animal! Is it pure ice?

Define "ice". Define "pure".

Ice=frozen water in this case! Pure in this scenario; i was referring to mostly! ( I be didn't know I had to be so precise!)

[orin stepanek]

Nicely done stereo; it loos like the head of some kind of animal! Is it pure ice?

I don't think it is "pure ice", but ice and rocky mix...

:---[===] *

Thanks Boomer!

[neufer]

Is it pure ice?

Our Moon is the result of a glancing planetary collision with the Earth resulting in a mostly mantle moon.

If Helene was the result of a glancing collision with Dione the result would be a mostly ice moon.

[orin stepanek]

Is it pure ice?

Our Moon is the result of a glancing planetary collision with the Earth resulting in a mostly mantle moon.

If Helene was the result of a glancing collision with Dione the result would be a mostly ice moon.

Thanks Art!