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APOD

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

A snow covered road goes up a hill to a sky filled with stars. Arcs and halos in the sky ahead appear similar to a giant eye. Please see the explanation for more detailed information.A snow covered road goes up a hill to a sky filled with stars. Arcs and halos in the sky ahead appear similar to a giant eye. Please see the explanation for more detailed information.

Diamond Dust Sky Eye

Explanation: Why is there a huge eye in the sky? Diamond dust . That is an informal term for small ice crystals that form in the air and flitter to the ground. Because these crystals are geometrically shaped , they can together reflect light from the Sun or Moon to your eyes in a systematic way, causing huge halos and unusual arcs to appear. And sometimes, together the result can seem like a giant eye looking right back at you. In the featured image taken in the Ore Mountains of the Czech Republic last week, a bright Moon rising through ice fog -filled air resulted in many of these magnificent sky illusions to be visible simultaneously. Besides Moon dogs , tangent arcs , halos , and a parselenic circle , light pillars above distant lights are visible on the far left, while Jupiter and Mars can be found just inside the bottom of the 22-degree halo .

Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

Date December 25, 2024
Credit Image Credit & Copyright: Jaroslav Fous
Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
A service of: ASD at NASA / GSFC,
NASA Science Activation & Michigan Tech. U.