Attractions

On the 6,791-foot peak of Mount Locke, the observatory was built in 1932 after a bequest from William J. McDonald, amateur astronomer. The site was selected because of clear air, high ratio of cloudless nights, distance from concentrations of artificial lights, and dust- and radiation-filtering growths of shrubs and timber. The original instrument was an 82-inch reflector; a 107-inch reflector is in a larger dome.

The Hobby-Eberly Telescope (HET), the third largest in the world, was designed to specialize in spectroscopy, the technique astronomers use to break down light into its component wavelengths. The telescope was built and is owned by a consortium of five universities. Interpretive programs in the George T. Abell Gallery highlight the HET's design and purpose. Take a free self-guided tour of the Abell Gallery. A more extensive guided tour of the HET is available with admission charge. For those driving RVs, limited-seating shuttle service is available from the visitors center for guided tours only.

The visitors center, at the foot of Mount Locke, is open 9 a.m.–5 p.m. daily. Solar viewings are presented at 11 a.m. and 2 p.m. daily. General admission charge required for the solar viewing and Decoding Starlight exhibit at the visitors center. Guided tours (charge) of the large telescopes are at 11:30 a.m. and 2:30 p.m. daily and also include the solar viewing and exhibit admission. Each Tuesday, Friday and Saturday evening, the center conducts "Star Parties," with telescopes set up by the observatory. An alternate program is held in the event of inclement weather. Once a month, visitors can view celestial objects through the 107-inch telescope by reservation with the visitor center. (Very popular and sometimes booked months in advance.) Charge for large telescope viewing. Closed Thanksgiving, Christmas and New Year's Day. The observatory is 16 miles northwest via Texas 118, Spur 78. 432/426-3640. www.McDonaldObservatory.org.