APOD: Stereo Helene (2019 Jun 15)

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APOD: Stereo Helene (2019 Jun 15)

Post by APOD Robot » Sat Jun 15, 2019 4:06 am

Image 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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Re: APOD: Stereo Helene (2019 Jun 15)

Post by BDanielMayfield » Sat Jun 15, 2019 11:31 am

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.

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Last edited by BDanielMayfield on Sat Jun 15, 2019 12:53 pm, edited 1 time in total.
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Re: APOD: Stereo Helene (2019 Jun 15)

Post by orin stepanek » Sat Jun 15, 2019 12:34 pm

Nicely done stereo; it loos like the head of some kind of animal! :D Is it pure ice?
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Re: APOD: Stereo Helene (2019 Jun 15)

Post by Chris Peterson » Sat Jun 15, 2019 12:45 pm

orin stepanek wrote:
Sat Jun 15, 2019 12:34 pm
Nicely done stereo; it loos like the head of some kind of animal! :D Is it pure ice?
Define "ice". Define "pure".
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Re: APOD: Stereo Helene (2019 Jun 15)

Post by Boomer12k » Sat Jun 15, 2019 8:37 pm

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...

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Re: APOD: Stereo Helene (2019 Jun 15)

Post by Boomer12k » Sat Jun 15, 2019 8:39 pm

orin stepanek wrote:
Sat Jun 15, 2019 12:34 pm
Nicely done stereo; it loos like the head of some kind of animal! :D Is it pure ice?
I don't think it is "pure ice", but ice and rocky mix...

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Re: APOD: Stereo Helene (2019 Jun 15)

Post by orin stepanek » Sun Jun 16, 2019 12:24 pm

Chris Peterson wrote:
Sat Jun 15, 2019 12:45 pm
orin stepanek wrote:
Sat Jun 15, 2019 12:34 pm
Nicely done stereo; it loos like the head of some kind of animal! :D 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!) :roll:
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Re: APOD: Stereo Helene (2019 Jun 15)

Post by orin stepanek » Sun Jun 16, 2019 12:26 pm

Boomer12k wrote:
Sat Jun 15, 2019 8:39 pm
orin stepanek wrote:
Sat Jun 15, 2019 12:34 pm
Nicely done stereo; it loos like the head of some kind of animal! :D Is it pure ice?
I don't think it is "pure ice", but ice and rocky mix...

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Thanks Boomer! 8-)
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Re: APOD: Stereo Helene (2019 Jun 15)

Post by neufer » Sun Jun 16, 2019 3:59 pm

orin stepanek wrote:
Sat Jun 15, 2019 12:34 pm

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.
Art Neuendorffer

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Re: APOD: Stereo Helene (2019 Jun 15)

Post by orin stepanek » Mon Jun 17, 2019 11:10 am

neufer wrote:
Sun Jun 16, 2019 3:59 pm
orin stepanek wrote:
Sat Jun 15, 2019 12:34 pm

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!
Orin

Smile today; tomorrow's another day!