Vietnamese-American astronomer who, in 1992 with astronomer David C. Jewitt, was the first to discover something orbiting our Sun beyond the orbits of Pluto and Neptune. The object, called 1992 QB₁, confirmed the existence of the Kuiper Belt, a collection of comet-like objects that orbit our Sun at a distance of 30-50 astronomical units (1 AU is the distance from the Earth to the Sun). Since then many more objects in the Kuiper Belt have been discovered by Luu and others.