In 1992, the discovery of a small object unlocked a big secret: that the solar system was far more vast than we'd ever imagined. Before, we'd only confirmed the existence of lonely, strange, cold Pluto, in a region of space called the Kuiper Belt. The Kuiper Belt is a grouping of icy objects located in an area just outside the orbit of Neptune—like a colder, more watery asteroid belt. Up until 1992, it had been strictly theoretical because no one had observed anything beyond Pluto. The discovery of 1992 QB1 marked only the second time an object in the Kuiper Belt had been found. In the next few years, discoveries of these small, cold worlds snowballed—80+ were found between 1992 and 1999, and hundreds are known today. With the outer solar system surveys at Mauna Kea and La Palma observatories in the 1990s, we finally began to unlock the "third zone" of the solar system as something more than theoretical.