The Andromeda Galaxy, August 2004.
© National Aeronautics & Space Administration / Science & Society
Infrared view taken with NASA's Spitzer Space Telescope which reveals new insights. This 24-micron mosaic is the sharpest image ever taken of the dust in another spiral galaxy. This is possible because Andromeda is only 2.5 million light-years away from the Milky Way. The Spitzer multiband imaging photometer's 24-micron detector recorded 11,000 separate snapshots. Asymmetrical features are seen in the prominent ring of star formation. The ring appears to be split into two, forming the hole to the lower right. These features may have been caused by interactions with satellite galaxies around Andromeda as they plunge through its disk. Delicate tracings of spiral arms within this ring reach into the very centre of the galaxy. One sees a scattering of stars within Andromeda, but only select stars that are wrapped in envelopes of dust light up at infrared wavelengths.