The Sky's the Limit at the McDonald Observatory

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I'll be the first to admit I had not heard of the McDonald Observatory which is just outside of Fort Davis. Built in the 1930's by the University of Texas and the University of Chicago, it is now operated as part of the University of Texas at Austin. Chris had stumbled on its existence when researching our trip in the area and though it would be a great place to visit, thus our staying at Fort Davis State Park, only about a 15 minute drive apart.

The Clouds Starting to Part as We Head Up

Entrance Sign at McDonald Observatory with Telescope in Distance

The cold and clouds had departed from the area and we were left with mainly clear skies and warmer temps. We headed up to the visitor center for the morning tour. This place is WAY up in the mountains and I was grateful we were just driving the Jeep and not the motor home. There weren't many others there for the tour so it was just six of us and the tour guide Dan which made for a good group size. We started with a short lecture session in the auditorium giving us some background as well as showing us some close up photos and videos of the sun.

Next we headed on the little tour bus further up the mountain to see the Harlan J Smith telescope. At 107" diameter, it was the third largest in the world when build in the late 1960's. It is definitely big and an impressive instrument. Dan demonstrated how the floor can move up and down to help with maintenance and also moved the telescope in several different orientations. Next he moved the dome around to align the opening with the telescope. The only thing he could not do was actually open up the cover since the outside conditions were not right. In fact, the temperature in the observatory was being controlled to 41F the day we were there because that was the expected temperature for later that night when the dome would be opened and they wanted everything to be at equilibrium when the telescope was in use.

Harlan J Smith Telescope

Our Tour Guide Dan Used A Wired Remote to Position Telescope

Outside with Viewing Port Closed

Next tour stop was to another side mountain and the Hobby-Eberly Telescope (HET). This one is not at all like what most people picture when they think of a telescope. In fact, Dan described how it works before we went into the viewing room, since we would likely be baffled at what we were seeing. This is a BIG telescope with a 30 foot diameter primary mirror. It is not one huge mirror but instead made up of 91 hexagonal mirrors, each slightly curved and mounted to produce the curvature needed to replicate a large mirror.

Even so, it was tough to comprehend since there is no tube around the optics. All the mirrors are mounted to a superstructure and visible to any visitors. This telescope was designed in such a way that it doesn't have as many degrees of freedom. Which means it cannot always point to all areas of the sky the other telescope can. So, unlike the first telescope on the tour where researchers actually come in and run the telescope during their allotted time slot, the HET is run by a group of local astronomers and technicians conducting experiments for researchers that never need to visit the facility.

HET and Its Unique Dome

After the tour, we decided to tour the area on our own, but were hungry so we stopped at the StarDate Cafè for a reasonable lunch. The other two couples had lunch as well so we chatted and learned that one of them were on a cross country bicycle trip but had rented a car to come up and visit the observatory. We talked to them about our adventure 25 years ago and wished them luck in the cold weather as they head towards Florida.

We drove around the area on our own which is permitted whether you paid for the tour or not. This allowed us to take pictures and see all the views the mountains provide. In fact the tour only got us into one area we couldn't get to on our own, but the tour was still well worth it and a highlight of the trip here. We decided the weather looked good to attend the star party tonight, but we had not dressed for an evening outside on top of the mountain. So we headed back to the campgrounds for dinner and warmer clothing. We stopped on our way to check out a huge radio telescope. It is part of ten located around the country monitoring the skies to eavesdrop on ET's phone call home, I suppose.

Incredible Views from Observatory Grounds

Cactus in Bloom

Harvard Radio Astronomy Station

When we got back to the visitor center just around sunset, there were close to a hundred people there. It wasn't clear where they all came from since there doesn't seem to be that many places to stay in Fort Davis. We started the program sitting outside while the tour guide did his best to point out the various stars and constellations. His job was made difficult by the fact the moon was a couple days from being full. So the ambient light from it was making some faint stars nearly impossible to see. After about 45 minutes of this, we wandered the grounds and checked out the 5 or 6 smaller telescopes that were pointed to different stars, nebulae, or the moon. Initially the lines were long enough that the wait was about 10 minutes, but as people cleared out, we were able to go back and check out some of the telescopes a second time.

Before we left, I got out the tripod and camera and did some night shots, not of the skies since the moon was too bright, but did get some interesting ones of the smaller telescope domes.

Smaller Telescopes Used for Star Party

Smaller Dome with Large Dome in Distance

Our last full day in Fort Davis found us going back up to the top of Skyline Drive to do a out and back hike that took us over the actual Fort. It was interesting to be able to see all the buildings clearly now. We then spent the afternoon at the library preparing for the trip to Big Bend and beyond.

The Fort at Fort Davis from Above

The Trail Signs Allow Intersting Shots