Astronomy Picture of the Day - Ice Halos by Moonlight and Sunlight

NASA ^ | 9 Jan, 2026 | Image Credit & Copyright: Antonella Cicala

[MtnClimber]

Explanation: Both Moon and Sun create beautiful ice halos in planet Earth's sky. In fact, the two brightest celestial beacons are each surrounded by a complex of ice halos in these photos of the sky above Chamonix-Mont-Blanc in France. The panels were recorded one night (left) and the following day at the end of December 2025. Similar ice halos appear in moonlight and sunlight because they are all formed through the geometry of flat, hexagonal ice crystals. The ice crystals reflect and refract light as they flutter in the cold atmosphere above the mountain resort. In the pictures both Moon and Sun are surrounded by a more commonly seen 22 degree circular halo. Bright and sometimes colorful patches at the intersections of the 22 degree circular halos with the indicated parselenic and parhelic arcs are also known as Moon dogs and Sun dogs. (Editor's note: Annotations updated by Marcella Pace)

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TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: apod; nasa

[MtnClimber]

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[MtnClimber]

[No name given]

Wow.

[MtnClimber]

Pinging the APOD list

🪐 🌟 🌌 🍔

[Diogenesis]

[Presbyterian Reporter]

When I lived in northern US we called the ice halos Sun Dogs.

[BenLurkin]

We used to call them “rings” as in “there’s a ring around the sun”

[Salamander]

We called them “Aw dammit snow is coming “

[BenLurkin]

Exactly.

[Salamander]

😬🥶🥶

[Diana in Wisconsin]

Beau took a few pictures of them when he was out raccoon hunting the other night. They didn't really capture how cool they look, otherwise I'd post them.

We get Sun Dogs in the winter months up here which are extremely cool:

[norwaypinesavage]

.Same for me. We would see them on very cold mornings as the sun was rising.

[MtnClimber]

Cool photo. Looks cold.

[MS.BEHAVIN]

Thanks so much!
I am reading “The Summoner” By Gail.Z. Martin.
In the story, a ring around the moon meant a king had died.

Pretty good book!

[telescope115]

Some really busy ice crystals in that second picture!