Artist's conception of the spiral structure of the Milky Way with two major stellar arms and a central bar. "Using infrared images from NASA's Spitzer Space Telescope, scientists have discovered that the Milky Way's elegant spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars. Previously, our galaxy was thought to possess four major arms."
NASA/JPL-Caltech/R. Hurt
2008-06-03
<a rel="nofollow" class="external free" href="http://www.spitzer.caltech.edu/images/1925-ssc2008-10b-A-Roadmap-to-the-Milky-Way-Annotated-">http://www.spitzer.caltech.edu/images/1925-ssc2008-10b-A-Roadmap-to-the-Milky-Way-Annotated-</a>