#light spectrum

Young blue stars circling the galactic center dominate the Andromeda Galaxy in this image taken in ultraviolet! About 2.5 million light-years away, the Andromeda Galaxy, also known as M31, really is our galactic neighbour. Spanning about 230,000 light-years, it took 11 different image fields from NASA’s Galaxy Evolution Explorer (GALEX) satellite telescope to produce this gorgeous portrait of the spiral galaxy in ultraviolet light in 2003. Its spiral arms stand out in visible light images, Andromeda’s arms are sites of intense star formation. They have been interpreted as evidence that Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago. The Andromeda galaxy and our own comparable Milky Way galaxy are the most massive members of the Local Group of galaxies and are projected to collide in several billion years – perhaps around the time that our Sun’s atmosphere will expand to engulf the Earth.

Image Credit: NASA, JPL-Caltech, GALEX