Panorama from the receiver platform on the GBT (about 400 feet above the ground). Above the front edge of the main dish, one can see the 140-foot (43 meters) Telescope, the largest equatorial telescope in the world. It was retired from NSF-supported research about a decade ago and is now being used in collaboration with MIT's Lincoln Laboratory to study the turbulent properties of the Earth's Ionosphere. A radar dish at Millstone Hill Observatory in Westford, MA bounces a radio beam off a satellite and the 140-foot Telescope picks up the radar echo. The 140-foot Telescope has a huge ball bearing 17 feet and 5 inches across (5.31 meters) made of steel with nickel-iron for the equatorial mount. Construction of the telescope was delayed because the original ball bearing was too brittle. Westinghouse East Pittsburg was contracted to create the single-cast bearing made of higher quality steel. The 140-foot Telescope was completed in 1965. Just to the right of the 140-foot Telescope is the service tower. When the receivers need to be switched or serviced, the telescope is tilted down so the receivers are next to the service tower.
Continuing right is 40-foot Telescope that is used solely for the education program of Green Bank. It is the one my team used in the Chautauqua short course to find the new arm of the Milky Way. Continuing right are the 85-1 Tatel Telescope and the 20-meter Telescope. On the right side of the image you can see the air strip. Above the center of the air strip from this viewing angle is the Jansky Laboratory and the Science Center.
Near the right edge of the main dish you can see four maintenance workers on the dish panels for a scale reference.
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last updated: September 14, 2011