http://photojournal.jpl.nasa.gov/catalog/PIA19341

Astronomers using data from NASA's Wide-field Infrared Survey Explorer, or WISE, are helping to trace the shape of the Milky Way's spiral arms. This illustration shows where WISE data revealed clusters of young stars shrouded in dust, called embedded clusters, which are known to reside in spiral arms. The bars represent uncertainties in the data. The nearly 100 clusters shown here were found in the arms called Perseus, Sagittarius-Carina, and Outer -- three of the galaxy's four proposed primary arms. The Sun is located in a spur to an arm, or a minor arm, called Orion Cygnus.

Another artist's version of this image based on Spitzer data can be seen at PIA10748 => http://photojournal.jpl.nasa.gov/catalog/PIA10748

JPL manages and operates WISE for NASA's Science Mission Directorate in Washington. The spacecraft was put into hibernation mode in 2011, after it scanned the entire sky twice, thereby completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify potentially hazardous near-Earth objects.