On Oct. 10, 1604, a young assistant to the German astronomer Johannes Kepler looked up in the sky and saw a brilliant light that had never been there before. Located in the serpent-bearer constellation Ophiuchus, the object shone brighter than any other star in the heavens. Over the next few nights, the body grew even more luminous, rivaling the glow of the solar system's biggest planet, Jupiter. Kepler himself got his first clear view on Oct. 17. Over the next year, he charted the course of the "new star" with naked-eye observations because the telescope hadn't yet been invented.