The heat of the Pinwheel

Spiral galaxies are among the most beautiful objects in the sky, and one of the most beautiful of them is M101, also known as the Pinwheel Galaxy. It's a reliable favorite among amateur astronomers because it's big, bright, and located near the north pole of the sky, so it's easy to find for a big part of the year. I've seen it many times through a telescope, but not quite like the way NASA's Wide-field Infrared Survey Explorer (WISE) saw it: glowing fiercely in colors our eyes cannot detect: