Astronomy Picture of the Day

Explanation: What glows in the night? This night, several unusual glows were evident -- some near, but some far. The foreground surf glimmers blue with the light of bioluminescent plankton. Next out, Earth's atmosphere dims the horizon and provides a few opaque clouds. Further out, the planet Venus glows bright near the image center. If you slightly avert your eyes, a diagonal beam of light will stand out crossing behind Venus. This band is zodiacal light, sunlight scattered by dust in our Solar System. Much further away are numerous single bright stars, most closer than 100 light years away. Furthest away, also rising diagonally and making a "V" with the zodiacal light, is the central band of our Milky Way Galaxy. Most of the billions of Milky Way stars and dark clouds are thousands of light years away. The featured image was taken last November on the Iranian coast of Gulf of Oman.