On This Day: Kuiper Belt Is Discovered

On Aug. 30, 1992, astronomers detected an object orbiting the sun beyond Pluto for the very first time. It was the first Kuiper Belt object ever observed.

Before then, Pluto was believed to be the most distant planetary body of our solar system. No one had seen anything orbiting farther out because these so-called Kuiper Belt objects were far too faint to detect with the technology they had at that time.

With new digital imaging techniques, astronomers were able to detect a new and tiny world orbiting 4 billion miles beyond Neptune. Officially designated 1992 QB1, this 100-mile-wide (160 kilometres) object was thousands of times fainter than Pluto. Now astronomers have confirmed more than two thousand objects orbiting out there in what is now known as the Kuiper Belt.