This ground-based image shows the full extent of the Andromeda Galaxy, also known as Messier 31 or M 31. The Andromeda Galaxy appears very large in the sky — several times the size of the full Moon (although much fainter). Hubble is designed to make highly detailed observations of much smaller patches of sky: the space telescope’s observations of the Andromeda Galaxy show individual stars and clusters rather than the broad spiral structure visible here. Wide-field images like this one give a broad overview.
ESA/Hubble & Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)