The Andromeda Galaxy is one of the most impressive galaxies to observe because of its size and distance — only about 2.5 million light years. While comparative sizes have changed over the years, recent data suggests the Andromeda Galaxy is only slightly larger than the Milky Way in total mass, but contains about 1 trillion stars compared to our 200 or so billion in the Milky Way. While most galaxies are moving away from us (measured by redshift) the Andromeda is moving towards us (blueshift) at the rate of 165 miles per second. At this rate, it will collide/merge with the Milky Way in about 4 billion years.
A very wide-field shot of the Andromeda Galaxy — one of the of few objects so big, no telescope is required. Taken with a Canon T4i and 200MM EF-L lens, stopped down to f/4. 37 180s exposures.
Resolution ........ 4.567 arcsec/pix Rotation .......... 89.483 deg Focal ............. 203.24 mm Pixel size ........ 4.50 um Field of view ..... 6d 19' 13.0" x 4d 7' 36.6" Image center ...... RA: 00 42 59.566 Dec: +41 23 49.61