This image shows M82, also known as the "Cigar galaxy," in infrared light, as observed by NASA's Spitzer Space Telescope back in 2005. Astronomers discovered in early 2014 that a supernova had exploded in a particularly dusty region of M82. Spitzer has since taken a series of observations of the region. In the image, light from Spitzer's infrared channels are colored blue at 3.6 microns and green at 4.5 microns.