M31 – Andromeda Galaxy

Assembled from a total of 7,398 exposures taken over 411 individual pointings of the telescope, this image of our nearest major galactic neighbor, M31, is the largest Hubble mosaic to date. The 1.5 billion pixels in the mosaic reveal over 100 million stars and thousands of star clusters embedded in a section of the pancake-shaped disk of M31, also known as the Andromeda Galaxy. Though the galaxy is over 2 million light-years away, Hubble is powerful enough to resolve individual stars in this 61,000-light-year-long stretch of the disk. It’s like photographing a beach and resolving individual grains of sand.