Blue and Red Galaxies Evolution Diagram
The typical blue spiral galaxy (top) continues to form stars actively until it collides with another galaxy. At that point, an active galactic nucleus (AGN) is formed that depletes the galaxy of dust, slowing star formation and changing the color to red. But the Milky Way and Andromeda galaxy both seem to be shifting to red on their own (bottom), without a collision to urge them along.
PanSTARRS and Andromeda Galaxy Sweden Heden
P-M Heden took this image of Comet PanSTARRS and the Andromeda Galaxy from Tänndalen, Sweden. The image was released on April 3, 2013.
The Galaxy Next Door
Hot stars burn brightly in this new image from NASA's Galaxy Evolution Explorer, showing the ultraviolet side of a familiar face. At approximately 2.5 million light-years away, the Andromeda galaxy, or M31, is our Milky Way's largest galactic neighbor. The entire galaxy spans 260,000 light-years across—a distance so large, it took 11 different image segments stitched together to produce this view of the galaxy next door.
Pan-STARRS and Andromeda
Skywatcher Victor Rogus took this image of the Comet Pan-STARRS and the Andromeda galaxy from Jadwin, Missouri on April 5, 2013.
Comet Pan-STARRS and M31
Skywatcher Victor Rogus took this image of the Comet Pan-STARRS and the Andromeda galaxy from Jadwin, Missouri on April 5, 2013.
Microquasar Location in M31
The Andromeda Galaxy (M31): Crosshairs show location of microquasar.
Measuring the Drift of the Andromeda Galaxy
This illustration shows one of the regions in the neighboring Andromeda galaxy where astronomers aimed the Hubble Space Telescope to make precise measurements of the galaxy's lateral motion. As the galaxy drifts through space, the stars will appear to uniformly move against the far-more-distant background galaxies, which remain fixed on the sky. Image released May 31, 2012.
Halo of Andromeda Galaxy Used to Measure Its Drift Across Space
This composite image shows a region in the halo in the neighboring Andromeda galaxy that astronomers used to precisely measure the galaxy's sideways motion on the sky. Image released May 31, 2012.
Collision Scenario for Milky Way and Andromeda Galaxy Encounter
This illustration shows the inevitable collision between our Milky Way galaxy and the Andromeda galaxy approximately 4 billion years from now. The galaxies are moving toward each other under the inexorable pull of gravity between them. A smaller galaxy, Triangulum, may be part of the smashup. Image released May 31, 2012.
Nighttime Sky View of Future Galaxy Merger
This series of photo illustrations shows the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years. The sequence is inspired by dynamical computer modeling of the inevitable future collision between the two galaxies. Image released May 31, 2012.
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