While testing a flight simulator, test pilot John Stewart found himself transported to a crashed UFO where he was met by a dying alien. Before he died, the alien gave John a green ring and a uniform. John discovered that Abin Sur had been part of an intergalactic peacekeeping force known as Green Lanterns. Directed by a blue-skinned race known as the Guardians of the Universe, the Green Lanterns that used special rings, which allowed them to fly, survive in space, and does nearly anything the bearer can will. Only a 24-hour time limit (after which it needs to be recharged) and a weakness against anything yellow limited these rings.