Astronomy Picture of the Day

Explanation: Most bright stars in our Milky Way Galaxy reside in a disk. Since our Sun also resides in this disk, these stars appear to us as a diffuse band that circles the sky. The above panorama of a southern band of the Milky Way's disk was taken from Australia. A 40-minute exposure was used, and the colours were digitally enhanced. Visible are many bright stars, dark dust lanes, red emission nebulae, blue reflection nebulae, and clusters of stars. In addition to all this matter that we can see, astronomers suspect there exists even more dark matter that we cannot see.