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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 hazy night sky shows four lined up items. The closest two are lit-up buildings on hills. Looming large in the background, in alignment, is a gibbous Moon, distorted and reddened by the Earth's atmosphere. Across the Moon's face is a streak that is an airplane. Please see the explanation for more detailed information.A hazy night sky shows four lined up items. The closest two are lit-up buildings on hills. Looming large in the background, in alignment, is a gibbous Moon, distorted and reddened by the Earth's atmosphere. Across the Moon's face is a streak that is an airplane. Please see the explanation for more detailed information.

A Quadruple Alignment over Italy

Explanation: Why does this Moon look so unusual? A key reason is its vivid red color. The color is caused by the deflection of blue light by Earth's atmosphere -- the same reason that the daytime sky appears blue . The Moon also appears unusually distorted . Its strange structuring is an optical effect arising from layers in the Earth's atmosphere that refract light differently due to sudden differences in temperature or pressure. A third reason the Moon looks so unusual is that there is, by chance, an airplane flying in front . The featured picturesque gibbous Moon was captured about two weeks ago above Turin , Italy . Our familiar hovering sky orb was part of an unusual quadruple alignment that included two historic ground structures: the Sacra di San Michele on the near hill and Basilica of Superga just beyond.

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

Date March 4, 2025
Credit Image Credit & Copyright: Valerio Minato
Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
A service of: ASD at NASA / GSFC,
NASA Science Activation & Michigan Tech. U.