The Kuiper belt is a region of the Solar System beyond the planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but it is far larger-20 times as wide and 20 to 200 times as massive. On January 19, 2006, the first spacecraft mission to explore the Kuiper belt, New Horizons, was launched. The mission, headed by Alan Stern of the Southwest Research Institute, flew by Pluto on July 14 2015. Having completed its flyby of Pluto, New Horizons has maneuvered for a flyby of Kuiper belt object 2014 MU.