Fort Davis was the objective today. There were two things to see there. The first was historic Fort Davis National Historic Park, an army post established in 1854. It was astride the San Antonio to El Paso road. It served as an infantry and cavalry post until 1891 when it was decommissioned. There are quite a few restored buildings on the site. We visited all of them. This was also a location where the Buffalo Soldiers were stationed.

Next stop was the McDonald Observatory. This is a very cool place. The first telescope (82 inch reflector) was dedicated in 1939. A larger (107 inch) reflector was dedicated in 1969 largely funded by NASA. The newest scope is a 360 inch segmented mirror scope. The mirror is composed of 91 hexagonal segments. It is used as a spectrometer. They are looking for dark energy. Sounds like a Big Bang Theory episode.

Today's photo is of the mirror end of the 107 inch scope. When we visited, the technical staff was trying to attach an instrument for some visiting astronomer. What you see is the rear of the mirror with lots of black counterweights which are used to keep the mirror true as it changes angle with the earth's gravitational field.