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.

2025 November 3
A wide angle image of the night sky is punctuated by
a radio telescope on the lower left. Two bands of light
run through the sky: the Milky Way and zodiacal light.
The bands intertwine like a double helix. Near the top
is an orange orb that is a totally eclipsed moon.
Please see the explanation for more detailed information.

A Double Helix Lunar Eclipse
Image Credit & Copyright: Chunlin Liu

Explanation: The image was timed to capture a total lunar eclipse -- but it came with quite a twist. First, the eclipse: the fully Earth-shadowed Moon is visible as the orange orb near the top. The eclipsed Moon's orange color is caused by a slight amount of red light scattered first by Earth's atmosphere, adding a color like a setting Sun. Now, the twist: one of the apparent double helix bands is the Milky Way, the central disk of our home galaxy. The second band is zodiacal light, sunlight scattered by dust in our Solar System. The reason they cross is because the plane where dust orbits our Sun is tilted relative to the plane where stars orbit our Galaxy. This well-known tilt is shown dramatically in the featured wide-angle Mercator-projectedhorizon to horizon, captured in early September from Mingantu Observing Station in Inner Mongolia, China

Tomorrow's picture: comet sky


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