English: A new era in stellar astronomy began five years ago when the Chandra X-ray Observatory first opened its sunshade to focus on former supernova Cassiopeia A. Sensitive to invisible x-ray light, Chandra can see the heat given off by massive stellar objects regardless of their distance. This ability to peer into the overwhelming darkness of space has revealed a hidden thermal universe previously veiled by the dominance of visible light. From the dark depths of space, Chandra has significantly elevated our understanding of black holes. Known for their ability to engulf everything around them, today we can measure a black hole's speed of spin, the limits of their gravitational influence and how many there are. Chandra has also been a window into galactic evolution. From its vantage view in space, the telescope observed a violent collision of the Antennae galaxies. Galactic collisions could promote the formation of new stars and planets, and be in our own distant future as the Milky Way slowly drifts toward the Andromeda Galaxy. Half a decade later, Chandra has once again returned to origins to take another look at Cassiopeia A. The supernova remnant is a former star, having cast of its gaseous layer in a violent explosion. At 200 times the resolution of the original 'first light' photos, the new images of Cassiopeia A reveal a torrent of clouds and molecular jets surrounding the object. On only its fifth birthday, the Chandra X-ray Observatory is celebrating a long list of discoveries that have forever changed how we see the universe.