The dedication of the observatory was held in Washington, D.C. with attendees, from left: Dr. Richard M. Emberson, Lloyd V. Berkner, G. A. Nay, John W. Findlay, Ned L. Ashton, David S. Heeschen and H. Hockenberry The gentlemen are pictured with a model of the 140’ Telescope.
Suzanne Stewart
Staff Writer
It’s hard to believe that radio astronomy began in an intrepid young man’s backyard in Wheaton, Illinois. All it took was curiosity, ingenuity and gumption for Grote Reber to build the very first radio telescope in 1938.
That moment in time led to the surge of astronomers turning to radio astronomy and looking for the answer to “what is out there?” when talking about outer space.
Retired astronomer and principal scientist at the Green Bank Observatory Dr. Jay Lockman made a presentation about the history of the GBO and naturally had to start with Reber – who’s original telescope is on display at the observatory.
“He heard that somebody had discovered there were radio waves coming from the universe, and he was an enterprising young guy,” Lockman said. “He built this dish next to his mom’s house in Wheaton, Illinois, a suburb of Chicago.
“He did it all out of his own pocket. Everything was of a size that he could buy at a hardware store. Nothing special. He had to build his own receivers and electronics. A truly remarkable guy.”
Reber managed to get a signal from out in the universe. Nobody knew what it was, but it repeated and was visible on the chart recordings he made.
“When the Milky Way went by, he got a bump,” Lockman explained, “and that was the start of radio astronomy.”
It was quickly put on hold by the start of World War II, but by the end of the war, with all the new technology available, scientists turned their eyes, once again, to the sky.
It wasn’t just American scientists either. In 1954, the Netherlands built an 85-foot telescope. Australia built one in 1953. By 1957, England had a 210-foot telescope and in 1956, France had a telescope, as well.
“In the mid-fifties, a lot of these projects were coming to fruition, but there was nothing in the United States,” Lockman said. “For various, complicated reasons, radio astronomy was born in the United States but didn’t get off the ground.
“Finally, the National Science Foundation was founded,” he continued. “It was the U.S. government’s way to fund pure research and they said, ‘we’ve got to get into the radio astronomy game.’”
This is when Green Bank entered the equation.
The NSF needed the perfect location for an observatory. A committee was formed to find the right place and there was a list of 10 criteria to go by.
Those included that the location should have a declining population with a projection of continued decline, no high-tension power lines, a broad valley surrounded by mountains that are ideally owned by the forest service, at least 50 miles from a city with a population of 5,000 and not near commercial routes.
The site also should provide attributes of a university campus and access to stores, theaters and recreational areas.
While Green Bank didn’t fit all the criteria, it was the closest to what they were looking for regarding remoteness.
“I talked to some of the people who were on the site selection committee maybe twenty years ago,” Lockman said. “I asked them what they thought about it. They said, ‘if we had to do it all over again, we would still pick Green Bank.’”
First runner up was Deerfield, Virginia, but due to its proximity to the Shenandoah Valley and Staunton, it wasn’t as ideal as Green Bank.
The Green Bank site was selected in 1955 and by 1956, the National Radio Quiet Zone was established.
The Quiet Zone is a 13,000 square foot area covering West Virginia, Virginia and a portion of Maryland where all transmitters must be pointed away from Green Bank and, in the case of Green Bank itself, transmitters are not allowed at all.
The National Radio Astronomy Observatory – NRAO – facility at Green Bank was dedicated on October 17, 1957, in an office in Washington, D.C.
“I don’t think this date was an accident because just a few weeks earlier, the Russians launched Sputnik, so all of a sudden, we were in a space race – and losing a space race – and I think that was a big impetus in those days for a lot of the work done,” Lockman said.
Almost a year later, October 16, 1958, the Tatel telescope, the 85-1, was dedicated at the observatory.
Some of the first science done at Green Bank. surprisingly, concerned climate change. Although the scientists didn’t know that at the time.
It was believed Venus could have the same climate as the Earth because it was similar in size and, while it was closer to the sun, it had clouds.
The radio telescope was used to peer through those clouds and the scientists discovered that the temperature of Venus was far from similar to Earth. It was 870 degrees Fahrenheit on the surface.
“You could melt lead on the surface of Venus,” Lockman said. “The real question became, ‘hey what does this mean?’ When I was in graduate school, we all had to take a course on climate change, and we were really concerned – what happened to Venus?
“It had a runaway greenhouse,” he continued. “The greenhouse that we have on Earth that keeps the heat in at night somehow went crazy on Venus. So, all astronomers started getting concerned about climate change fifty years ago.”
One of the most pivotal moments in radio astronomy history occurred at Green Bank in 1961.
Frank Drake, acclaimed astrophysicist and astrobiologist, devised the Drake equation, which is used in the Search for Extraterrestrial Intelligence – SETI.
“He used [the Tatel] telescope, looked at a couple nearby stars to see if there was anybody out there sending radio signals and that was the start of a long effort that has continued,” Lockman said. “I can give you the latest update – news as of today. Nothing.
“The search goes on.”
The observatory continued to grow and telescopes were added to the vast valley.
The 140-foot telescope was built to be a workhorse with a unique design. It required a large ball bearing that is 21 feet across.
The building of the telescope was met with a lot of issues.
“The contractor tried to make [the ball bearing] in a manner that resembled reassembling an orange from slices,” Lockman said. “Couldn’t do it.
“The polar shaft got shipped into [the county by train] in two pieces and then brought to the observatory,” he continued. “It was being reassembled at the base of the 149-foot structure when they discovered the steel it was made of was prone to a brittle stress factor and under certain conditions, it could have just snapped.”
The project was held up for years, but eventually a new solid ball bearing was made and was delivered by train.
“It was machined in a single piece, smaller so it could get through a tunnel,” Lockman said. “I think it was through Droop tunnel – and they did a mockup of the bearing because it had to come by train through that tunnel. They built a special railcar to move it, and it came through with a clearance on each side of about an inch.”
When the structure was lifted into place, it was lucky that a movie director was onsite and filmed the whole thing because a cable snapped and it dropped. It was a very dramatic and nerve wracking scene.
“Eventually it was done,” Lockman said. “It was dedicated October 13, 1965.”
In a complete 180 of what happened with the 140-foot, the 300-foot was designed and built swiftly, in less than two years at a cost of $1.2 million.
The 300-foot telescope, at left, was the first world’s largest moving telescope before it collapsed on November 15, 1988. The rubble, shown above, was cleared away, but the control building remains and is used for storage.
The bid was put out in March 1961, ground was broken in May 1961 and it was completed in the summer of 1962.
The telescope was different from anything else at the observatory. It was low to the ground and had a mesh-like dish.
“It was really low to the ground,” Lockman said, “They wanted to minimize the wind resistance. The higher it is, the stronger it has to be, so they made it low. There was a lot of sky it couldn’t get, so they dug a ditch so it could tip down even a little bit further.
The dish itself was kind of comical when considering how high tech the equipment is at the observatory.
“The thing about radio waves is, you need a really polished surface to reflect light, but radio waves can get reflected off of a rather crude surface and, in fact, the first surface of the 300-foot was Sear’s finest chicken wire,” Lockman said.
“It was damaged during installation,” he continued. “There was an ice storm that made some big ripples in it, so they did what anybody would do – they took a piece off and ran over it with a bulldozer. That didn’t help.
Regardless, the telescope was finished and up and operating in 1962. Unfortunately, it would not become known for the science it did, but instead for its demise.
On November 15, 1988, the 300-foot telescope collapsed in the middle of the night.
While speculation ran rampant – one tabloid newspaper blamed aliens – the real culprit was stress factors cracked a steel connector plate that was a key piece of the support structure.
Before its collapse, the 300-foot was the world’s largest moving telescope.
Its successor, the Green Bank Telescope, was dedicated in 2000, and is the world’s largest fully steerable radio telescope.
The historic telescopes are joined by 85-2 and 85-3 which join the 85-1 in the interferometer cluster; the 40-foot, the 20-meter and the Jansky Antenna.
