仙女座大星系的气晕
2020年9月3日 A Halo for Andromeda Digital Illustration Credit: NASA, ESA, J. DePasquale and E. Wheatley (STScI) and Z. Levay Explanation: M31, the Andromeda Galaxy, is the closest large spiral galaxy to our Milky Way. Some 2.5 million light-years distant it shines in Earth’s night sky as a small, faint, elongated cloud just visible to the unaided eye. Inv...