Greenbank National Radio Astronomy Observatory - West Virginia

Greenbank National Radio Astronomy Observatory - West Virginia

The GBT is described as a 100-meter telescope, but the actual dimensions of the surface are 100 by 110 meters. The overall structure of the GBT is a wheel-and-track design that allows the telescope to view the entire sky above 5 degrees elevation. The track, 64 m (210 ft.) in diameter, is level to within a few thousandths of an inch in order to provide precise pointing of the structure while bearing 7300 metric tons (16,000,000 pounds) of moving weight.

The GBT is of an unusual design. Unlike conventional telescopes, which have a series of supports in the middle of the surface, the GBT's aperture is unblocked so that incoming radiation meets the surface directly. This increases the useful area of the telescope and eliminates reflection and diffraction that ordinarily complicate a telescope's pattern of response. To accommodate this, an off-axis feed arm cradles the dish, projecting upward at one edge, and the telescope surface is asymmetrical. It is actually a 100-by-110-meter section of a conventional, rotationally symmetric 208-meter figure, beginning four meters outward from the vertex of the hypothetical parent structure.

The GBT's lack of circular symmetry greatly increases the complexity of its design and construction. The GBT is also unusual in that the 2,004 panels that make up its surface are mounted at their corners on actuators, little motor-driven pistons, which make it easier to adjust the surface shape. Such adjustment is crucial to the high-frequency performance of the GBT in which an accurate surface figure must be maintained.

Welcome to the National Radio Astronomy Observatory in Green Bank West Virginia!

The Observatory is home to the Robert C. Byrd Green Bank Telescope, the largest fully steerable dish in the world.

Astronomers use the Green Bank Telescope to unlock the secrets of the Universe.

Use the menu above to learn more or call the Science Center at Green Bank (304) 456-2150.

Green Bank Visitor Information

Directions and Maps
Airport directions
Directions to and from nearest cities (in PDF)
Here are several maps in PDF format:
Green Bank Site Map
Green Bank - Charlottesville Area
Green Bank - Pittsburgh Area:
Facilities for Observers and Official Visitors
Visitor Facilities and Policies
Visitor and Observers Reservation System

The Green Bank Dormitory is available for educational groups. Please note its use is for groups who have scheduled educational activities at GB. It is NOT for GBT observers.

Local Information
Information for Pocahontas County, WV
Information for West Virginia

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