|August 4, Wednesday: It rained pretty hard during the night, so we didn’t know what today would bring. But it stopped by the time we were ready to pack up and leave. We had planned on just driving home, but we passed the National Radio Astronomy Observatory at Green Bank and decided to find out about that.
The Green Bank Telescope (GBT) is designed to capture radio waves from the universe and analyze them. It’s known as radio astronomy. I never even knew such a thing existed. They have a number of telescopes used for different things. Scientists from around the country come and conduct research there and junior and senior high students come also. Just a few weeks ago a high school girl discovered a new pulsar after analyzing data that the GBT had collected.
We wandered around the science center and then saw a short movie. We knew we didn’t have any cell phone service while we were in Cass, and the GBT is the reason why. This particular site was chosen because the surrounding mountains shelter them from radio interference. There are no cell phone towers around. It’s on the 38th parallel (the 40th parallel is prime viewing for the Milky Way Galaxy) and 70% of Pocahontas County is owned by the government or state so there is not a lot of land available for other development. It’s important that the area surrounding the GBT has as little radio interference as possible.
The NRAO is located in a national radio free, or quiet, zone. They control a 10 mile radius where there are no cell phones. They have an installation that can detect interference. Then a group goes out to find it. In one case, they discovered that wildlife folks had put radio collars on flying squirrels to track where they went. NRAO had to shut down operations until the batteries in the transmitters quit. The tour leader explained that interference can be caused by pace makers, hearing aids, and other medical devices. They only use diesel powered vehicles on site because the spark plugs in gasoline engines cause too much interference.
After the inside program we got on a bus and traveled around the site. There were about 8 different telescopes, some were still used, and some have been shut down. One of them uses a ball bearing that is 17.3 feet in diameter. Big.
The GBT (employees call it the Great Big Thing) was the star of the show. It is huge! If you’re familiar with a satellite dish to receive TV signals, then you have an idea of what it looks like. It’s a big dish with a receiver positioned above the dish. The dish gathers the radio waves and focuses them on the receiver. The radio waves this telescope gathers are from 15 million light years away. The telescope is almost as tall as the Washington Monument. It weighs 17 million pounds and can be pointed with an accuracy of one arcsecond. That’s equivalent to the width of a human hair seen from 66 feet away. The surface is made up of 2004 metal panels and is almost 2.3 acres. They can turn the telescope 360 degrees in 10 minutes. It is the largest steerable structure in the US and maybe the world.
After that we started on the last leg of the journey. We drove up WV 28 that is a nice little road that winds up the creek valleys between the mountains. It just meandered along and was a lovely ride. Then we hit WV 55, a four lane highway across the mountains and into Strasburg, VA. We went through some pretty deep cuts. I’m sure it’s called Robert Byrd Highway. That guy really brought some money back to WV – and it surely needed all it could get.
We had one stop in Winchester at Camping World. While we were on the road a Camping World rep called Larry to tell him that he had won a table top grill in a raffle at the Rally. We had made arrangements to pick it up in Winchester. So the Rally and the whole trip was a great adventure. Now we’re home and ready to work on the basement again.