NRAO

 

 

The History of the Green Bank Observatory

The National Radio Astronomy Observatory (NRAO) at Green Bank, West Virginia, was established in 1956 as the first national observatory in the United States funded by the National Science Foundation (NSF). Chosen for its remote location and natural mountain shielding, it has been the site of some of the most significant discoveries in modern astrophysics.

The National Radio Quiet Zone

A defining feature of the Green Bank site is its location within the National Radio Quiet Zone (NRQZ). Established in 1958 by the FCC and the Interdepartment Radio Advisory Committee, the zone covers approximately 13,000 square miles across West Virginia and Virginia. Within this area, radio transmissions are strictly limited to prevent interference with the sensitive equipment at the observatory, creating a unique environment where modern cellular and Wi-Fi signals are largely absent.

Major Milestones and Telescopes

The history of Green Bank is marked by the construction and operation of massive instruments:

• The 85-foot Tatel Telescope (1958): The site’s first major telescope, famous for Project Ozma.

• The 300-foot Telescope (1962): At its completion, it was the largest moving telescope in the world. It famously collapsed in 1988 due to a structural failure.

• The 140-foot Telescope (1965): The world’s largest equatorially mounted radio telescope, which remains a feat of engineering today.

• The Robert C. Byrd Green Bank Telescope (2000): Often called the "Great Big Thing" (GBT), it is the world’s largest fully steerable radio telescope, standing higher than the Statue of Liberty.

Chronological Timeline

Year	Event
1956	The National Radio Astronomy Observatory (NRAO) is founded by the NSF in Green Bank, WV.
1957	Groundbreaking and official dedication of the Green Bank site (October 17).
1958	Completion of the 85-foot Tatel Telescope; National Radio Quiet Zone is established.
1959	First observations occur; Frank Drake discovers the radiation belts of Jupiter.
1960	Project Ozma: Frank Drake conducts the first scientific search for extraterrestrial intelligence.
1961	The Drake Equation is formulated at a meeting in Green Bank; 300-foot telescope begins construction.
1962	The 300-foot Telescope becomes operational; 40-foot educational telescope begins use.
1964	First NRAO interferometric measurements (using two 85-foot telescopes).
1965	The 140-foot Telescope is completed and begins observations.
1966	NRAO headquarters moves from Green Bank to Charlottesville, VA.
1967	First U.S. Very Long Baseline Interferometry (VLBI) observations are conducted.
1968	First pulsar discovered in a supernova remnant (the Crab Nebula) using Green Bank instruments.
1969	Formaldehyde is discovered in space, launching the field of interstellar chemistry.
1974	Detection of the radio source Sagittarius A* at the center of the Milky Way.
1987	The 40-foot Telescope is converted into a dedicated educational instrument for students and teachers.
1988	The 300-foot Telescope unexpectedly collapses on November 15 due to a gusset plate failure.
1989	Senator Robert C. Byrd secures funding for a replacement: the Green Bank Telescope (GBT).
1991	Groundbreaking for the Robert C. Byrd Green Bank Telescope.
2000	Dedication of the Green Bank Telescope (August 25) and "first light" observations.
2003	The Green Bank Science Center is dedicated to public education and tourism.
2010	The GBT measures the most massive neutron star known at the time.
2016	Green Bank Observatory separates from NRAO to become an independent NSF facility.
2023	The American Physical Society designates the Green Bank Observatory as an official Historic Site.

Scientific Legacy

From proving the existence of dark matter through flat galactic rotation curves to testing Einstein’s Theory of General Relativity with double-pulsar systems, Green Bank continues to be a cornerstone of global astronomical research. Today, it hosts the Breakthrough Listen project, the most extensive search for technosignatures from other civilizations to date.