For years, Pluto was known as the ninth planet and the most distant one in the solar system. But in 2006, astronomers reclassified Pluto as a dwarf planet because they realized that there were several other similar-size objects in deep orbit around our sun. Pluto is about two-thirds the size of the Earth’s moon, but it is the largest object in the Kuiper Belt, a band of rocky objects that orbits the sun at the edge of our solar system. The Kuiper Belt is named after Gerard Kuiper, the astronomer who founded the Lunar and Planetary Lab at the University of Arizona.
On Tuesday, NASA’s New Horizons spacecraft will reach Pluto, and soon it will send back the first-ever close-up photos of the famous dwarf planet. The UA's Flandrau Science Center and Planetarium, in collaboration with the Lunar and Planetary Lab, will celebrate the milestone by hosting Pluto Week, including the premiere of "Exploring New Horizons," a new FullDome planetarium show about the New Horizons mission.
The show’s premiere will be at 5 p.m. Tuesday, followed at 6 by a live NASA event next door at the Lunar and Planetary Lab, when the New Horizons spacecraft will re-establish contact with mission control. Then on Saturday, a special Summer Science Saturday event at LPL will feature family-friendly activities and lectures about Pluto, dwarf planets and asteroids.
Other showings of "Exploring New Horizons" at Flandrau are scheduled for 3 p.m. Wednesday and Thursday; 7 p.m. Friday; noon, 5 and 8 p.m. Saturday; and 3 p.m. Sunday. For more information about Pluto Week: http://flandrau.org/events/pluto-week.