Green Bank – National Radio Astronomy Observatory


By the time you roll into Green Bank, West Virginia, you’ve probably noticed that there’s almost nothing on the radio, and your cell phone doesn’t work.  Then you realize you haven’t seen a cell phone tower for most of the day.  Just as you start to think you’ve left all signs of technology behind, the world’s largest fully-steerable radio telescope appears ahead of you.

It’s because of this enormous dish antenna, and several others nearby at the National Radio Astronomy Observatory, that radio waves are frowned upon in this area.  These super-sensitive antennas are designed to pick up faint radio waves from millions of miles away — even a simple cell phone signal would blow them out.

I stopped at the visitor’s center, to find out if I could drive out for an up-close viewing of the big dish, which is officially named the Robert C. Byrd Green Bank Telescope (guess who helped out with the federal funding?).  I was told I couldn’t drive, but I could catch a ride on a tour, that was just about to begin.

The tour began with a video in an auditorium.  I was the only one there, so I got a private showing.  Then my guide and I boarded a diesel-engine bus — she explained that the spark from a combustion engine creates radio waves, which could interfere with the telescopes.  This is why many of the NRAO’s vehicles are 50-year-old antiques — more modern vehicles are packed with electronics.

The tour stopped at a viewing area, which was still quite a long way from the GBT.  But, this was the last spot where photography was allowed, once again, because of electronic interference.  I took a couple pictures, then dutifully turned off my digital camera.  I had left the cell phone in the car, or else I would have been required to turn it off, too.

The tour continued past several other skyward-pointing dishes, which are used for various purposes by visiting scientists.  The van stopped just outside the fence that surrounds the GBT.  I was allowed to step out and look at it for a moment.  Up close, it’s incredibly impressive.

The Green Bank Telescope (GBT) was completed in 2000.  It weighs 17 million pounds, making it the world’s largest land-based moving structure.  On the dish surface, there are 2,004 panels, and each one is adjustable, to make certain those faint signals are perfectly focused on the receiver.  The orientation video on the tour explained that the GBT is sensitive enough to see an individual slice of pepperoni on a pizza 3 miles away.  It’s not normally aimed at pizzerias, though.

Before you leave, check out the Grote Reber telescope near the parking lot.  Compared to the GBT, it looks like a toy, but it’s the real thing.  Reber built the world’s first radio telescope in 1937 in his backyard in Wheaton, Illinois.

Because of the Great Depression, Reber couldn’t find a job at any astronomical observatory, so he built the telescope himself, using his own money.

As you leave the NRAO, continue south on WV 28 to WV 66, which takes you to Cass, and the famous Scenic Railroad.

Note: This trip was first published in 2008.

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