In celebration of the 400th anniversary of Galileo’s first use of the telescope, the International Astronomical Union and UNESCO have declared 2009 to be the International Year of Astronomy (IYA 2009). As part of a world-wide celebration of this event, the U.S. Naval Observatory (USNO) will be sponsoring a free-admission Open House on Saturday, 4 April, from 3:00 pm to 10:00 pm. During that time the Observatory’s telescopes will be open for inspection, scientists will explain the mission of USNO’s Master Clock, exhibits will display the Observatory’s history and present work, and local amateur astronomers will share views through their telescopes.
The open house will coincide with world-wide activities promoted by the IYA, specifically the “100 Hours of Astronomy” activities taking place around the globe from April 2 through April 5. The main goal of this effort is to give as many people as possible the opportunity to look through a good-quality astronomical telescope. To this end, USNO’s open house should provide many opportunities for patrons to do so. In addition to safe observation of the Sun during the afternoon, the evening hours will feature a multitude of amateur telescopes that will be trained on the Moon, Saturn, plus a host of other interesting celestial sights.
Once on the grounds, visitors may tour the historic Building 1, home of the Observatory’s worldrenowned James M. Gilliss Library, and its 115 year-old 12-inch Alvan Clark refractor telescope, which will be set up for safe viewing of the Sun, weather permitting. The 26-inch “Great Equatorial” telescope, famous for its discovery of the moons of Mars in 1877 and still in use on every clear night, will also be open for inspection.