Telescope Nerd » Observatory Visits » McDonald Observatory: One of the largest telescopes in the world

McDonald Observatory: One of the largest telescopes in the world

The McDonald Observatory, otherwise known as the Hobby-Eberly Telescope, is located in Fort Worth, Texas, in the United States. During my trip around the United States, I spent a day visiting the observatory and it had a lot of events and scheduled things to do. From tours to other events, it seems like there is always something happening. I was unable to get a tour but I was able to drive around the area and walk the grounds a bit. The Hobby-Eberly Telescope is the centerfold of the observatory campus.

About the Hobby-Eberly Telescope
In the observatory’s large glass visitor room, I found a lot of information was available about the telescope. While I already knew large telescopes like this were kept in carefully controlled environments with temperature and humidity maintained to exacting standards, I learned a lot about the unique design of the Hobby-Eberly Telescope.

The Hobby-Eberly Telescope is a reflector telescope. It has a segmented primary mirror composed of 91 segments. These segments give the telescope an effective mirror diameter of 10 meters and it is specifically designed for spectroscopy work. The design of the telescope utilizes a system of a primary mirror and secondary mirror. The secondary mirror does the tracking while the primary mirror is locked onto a stellar object. The benefit of this unique design is two-fold: It saves the primary mirror from having to move while also saving money because only the second mirror is moving.

Layout of the McDonald Observator
I picked up my tickets at the visitor center and drove up to the center point section of the campus that contained the telescope. I noticed the layout of the campus was normal to similar observatories I’d visited, meaning I had to drive a mile or so uphill to reach the area where the telescope was. I took a picture that accurately shows the distance between the visitor center and the telescope, as you can see it’s not a short drive.

I took a stroll around the massive telescope and looked at it through the viewing glass. I had to take pictures of the telescope in pieces because of how big it was. There was an upper and lower viewing section. The visitor center was nice. From the parking lot to the cafeteria, the grounds of the observatory were well kept. There were various displays you can view to learn more about the observatory. One event that caught my attention involved hummingbirds that regularly visited the observatory due to the hummingbird feeders right outside the windows of the cafeteria.

Bonus information about the McDonald Observatory and Hobby-Eberly Telescope
The Hobby-Eberly Telescope is ideal for searching for planets around other stars. It excels at studying distant galaxies, exploding stars, black holes and more because of its ability to decode the light from stars and galaxies. It’s an 80 ton telescope, which is massive, and is lifted and positioned using air cushions. It utilizes a honeycomb design that’s made up of 91 hexagonal mirrors that form a reflecting surface.

It received a $40 million upgrade in 2016 that expanded its field of view to an area of sky 120 times larger than before. One thing to take note of is the tilt of the Hobby-Eberly Telescope, it’s different from most others you might encounter. Most telescopes tilt up and down, but the Hobby-Eberly consistently tilts at 55 degrees above the horizon. Also, the way this telescope is designed allows it to see up to 70% of the visible sky.

Astronomers submit proposals to the telescope’s queue. These proposals are then scheduled to be completed within 4 months of submission. This queue scheduling process makes the telescope well-suited for timing and studying certain targets and guarantees the telescope is used efficiently.

Would you like to learn more?
Do you want to learn more about McDonald Observatory? Or maybe you would like to visit? Check out their website for more right here: McDonald Observatory. They have a whole lot of activities including nighttime star parties. So I say give them a look!

Would you like to learn about the other largest telescopes in the world? The Telescope Nerd has written an article (with pictures) about them.