Green Bank Facts

Green Bank Facts

General Information; History; Funding History; Green Bank Telescope;


General Information

  • The Green Bank Observatory is home to eight telescopes including the Robert C. Byrd Green Bank Telescope (GBT)
  • Green Bank Observatory employs 100 people on the Green Bank site year-round, and 140 people during summer months
  • Approximately 40,000 visitors come to the Green Bank site each year
  • More than 3,500 students participate in Green Bank’s educational programs within the past year, representing states from all across the U.S.
  • Last year, 54 different groups came to spend at least one night and use the 40-ft educational telescope for research
  • We average 12-16 residential workshops each year, for ages ranging from middle school through undergraduate students, graduate students, and teachers, as well as the general public
  • Green Bank staff travel around the country and around the world to take part in educational programs and to talk about the science and technology of the Green Bank Observatory
  • The site technology development program typically works with 5-15 college/universities at any one time
  • 60% of the Green Bank staff are native from Pocahontas County and West Virginia
  • The National Radio Quiet Zone is administered for Green Bank Observatory and the Sugar Grove Research Facility
  • The site telescopes range in diameter from 40 feet – 330 feet (12 – 100 meters)


  • The Green Bank site was dedicated on October 17, 1957
  • The West Virginia Radio Astronomy Zoning Act was passed in 1957
  • The National Radio Quiet Zone was established in 1958
  • The first undergraduate summer students arrive in Green Bank in 1959
  • The first telescope was completed in 1958 – an 85 foot diameter telescope which remains on site today
  • The first NRAO interferometric measurements were in Green Bank in 1964 (with two 85 foot telescopes)
  • Ground breaking for the GBT was in 1991, it was dedicated in 2000, and went into operation in 2003
  • Full high frequency operation of the GBT was achieved in 2011.

Funding History

  • The Green Bank Observatory was originally funded by the National Science Foundation
  • The majority of the site buildings, telescopes, and facilities were either built by, or are owned by, the National Science Foundation
  • In 2012 95% of the funding for the site operations was provided by the National Science Foundation
  • In 2017 only about 66% of the site funding comes from the National Science Foundation, and this amount could change in the future.

The Green Bank Telescope

  • The GBT cost roughly $95,000,000 to build
  • The GBT is the largest fully-steerable telescope in the world
  • The GBT is running observations roughly 6,500 hours each year, more than most other observatories
  • For each hour of time available for science on the GBT, roughly 3-4 hours are requested
  • More than 600 individual scientists and students proposed to use the GBT within the past year
  • More than $25,000,000 has been invested in the GBT in the past five years by colleges, universities, the NSF, and the state of West Virginia
  • The surface of the GBT is perfectly smooth to a noise level of 260 microns (5 human hairs)
  • The pointing accuracy of the GBT is 2 arc seconds, able to resolve a quarter at 3 miles
  • The GBT weighs almost 17 million pounds and stands over 485 feet above ground level
  • The GBT’s collecting area is 2.3 acres and its diameter is 330 feet
  • The GBT operates 24 hours/day, 362 days/year