Milky Way Galaxy
Illustration courtesy NASA/JPL-Caltech
This 2008 illustration shows a revised look at our galaxy, the Milky Way. Scientists studying infrared images from NASA's Spitzer Space Telescope determined our galaxy's spiral has two major and two minor arms instead of four major arms, as was previously thought. The demoted arms can be seen as faint trails between the major arms, which emanate from the ends of the orange central bar.