The Houston Museum of Natural Science (abbreviated as HMNS) is a natural history museum located on the northern border of Hermann Park in Houston, Texas, United States. The museum was established in 1909 by the Houston Museum and Scientific Society, an organization whose goals were to provide a free institution for the people of Houston focusing on education and science. Museum attendance totals over two million visitors each year. The museum complex consists of a central facility with four floors of natural science halls and exhibits, the Burke Baker Planetarium, the Cockrell Butterfly Center, and the Wortham Giant Screen Theatre (formerly known as the Wortham IMAX Theatre). The museum is one of the most popular in the United States and ranks just below New York City's American Museum of Natural History and Metropolitan Museum of Art and the M. H. de Young Memorial Museum in San Francisco in most attendance amongst non-Smithsonian museums. Much of the museum's popularity is attributed to its large number of special or guest exhibits. History The initial museum organization was called the Houston Museum and Scientific Society, Inc., and was created in 1909. The museum's primary collection was acquired between 1914 and 1930. This included the purchase of a natural-history collection assembled by Henry Philemon Attwater and a donation from collector John Milsaps, the latter of which formed the core of the museum's gem and mineral collection. First housed in Houston's city auditorium, the collection was subsequently housed in the Central Library for seven years, and then at a site in the Houston Zoo in 1929. The museum's now wide-ranging education programs began in 1947 and, in its second year, hosted 12,000 children. The museum was officially renamed the Houston Museum of Natural Science in 1960. Construction of the current facility in Hermann Park began in 1964 and was completed in 1969. By the 1980s, the museum's permanent displays included a dinosaur exhibit, a space museum, and exhibits on geology, biology, petroleum science, technology, and geography. In 1988, the Challenger Learning Center was opened in memory of the Space Shuttle Challenger crew members that were lost during the shuttle's tenth mission. The center's aim is to teach visitors about space exploration. The Wortham IMAX Theatre and the offsite George Observatory were opened in 1989. Museum attendance was more than one million visitors in 1990. HMNS trustees determined that new state-of-the-art facilities, additional space, and renovations