McDonald Observatory

John wanted to see this observatory while we were in Texas, he just was not sure when or how we would fit that in. Yesterday, when we decided to take a short drive into the Davis Mountains, he suddenly realized that we were driving very close to the observatory and might as well stop and check it out. We stopped and signed up for a tour. Fortunately, it being spring break week, a lot of the volunteers were gone and the research astronomers were giving the tours. Our guide had worked there at least 30 years and had plenty of information to share with us .After a  lengthy explanation by him of the different telescopes and how they are used at the observatory, we left the visitors center to drive up to one of them on top of the mountain. At the building of the 107 inch  mirror telescope our guide had us climb up 70 steps to the floor where it is located.

The McDonald Observatory is one of the largest in the world open to public tours. Its location is ideal  because of its isolation, clear air and absence of city lighting.The telescope which we were privileged to see sits at an elevation of 6,791 feet, the highest elevation in Texas on a public road. We had clear visibility at this point; our guide estimated that we could see about 150 miles off into the distance, into Mexico, because of a certain mountain that was visible.

It probably was good that I had a chance to see the telescope as I was still under the misconception that scientists just peered directly into telescopes to get the information they needed. (Actually the image falls on a plate just like in a digital camera and is sent to a computer for viewing.) John had a lot more understanding of them and was happy that he had a chance to see a real one, not something just depicted in books or magazines.The telescope we looked at weights 160 tons and is so well balanced that it can be moved around by a one-half horse power motor. Our guide demonstrated how it and the dome above it rotate using computerized remote control. There is also an opening through which the telescope peers out, like shutters on a window. The telescope is used for star studies and searching for new planets. Another telescope in the complex is used with a laser beam reflected off a reflector on the moon (left by Apollo astronauts) to measure the exact distance to the moon and tracks the drift of the earth's continents. This helps to monitor the movement caused by plate tectonics. The Pacific plate is currently moving under the North American plate and Hawaii is moving toward California at the rate of 4 inches a year. Hang around long enough and you won't have to fly there.

The base of the telescope can be seen in the picture above, as well as one of the two pillars which support the telescope. It will not vibrate, even if the building vibrates, as the pillars which support it extend 60 feet below into bedrock and are isolated from the dome building. After the tour it was getting close to sunset, which made for a beautiful trip home through the mountains. That was a good time for wildlife to be out, and we saw two javelina (from the peccary family), a herd of mountain sheep and numerous deer.