Green Bank in Pocahontas County, West Virginia — The American South (Appalachia)

Ewen-Purcell Horn Antenna

Photographed by Bernard Fisher, August 7, 2012

1. Ewen-Purcell Horn Antenna Marker

Inscription. This horn antenna was used by Harold I. Ewen and Edward M. Purcell at the Lyman Laboratory of Physics at Harvard University in 1951 for the first detection of radio radiation from neutral atomic hydrogen gas in the Milky Way at a wavelength of 21 centimeters

Topics. This historical marker is listed in these topic lists: Air & Space • Communications • Education • Science & Medicine. A significant historical year for this entry is 1951.

Location. 38° 25.891′ N, 79° 49.085′ W. Marker is in Green Bank, West Virginia, in Pocahontas County. It can be reached from West Virginia Route 28/92 east of Cemetery Road (County Route 28/25), on the right when traveling south. Located at the National Radio Astronomy Observatory. Touch for map. Marker is in this post office area: Green Bank WV 24944, United States of America. Touch for directions.

Regionally, this marker is in West Virginia’s Potomac Highlands.

It is also in the American South,

specifically in the Upper South,

in Appalachia,

and specifically in Southern Appalachia. Globally, it is in North America,

the Western Hemisphere,

the Western World,

and

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the Anglosphere.

Historically, it finds itself in what was once the territory of the Mississippian Culture.

Other nearby markers. At least 8 other markers are within 8 miles of this marker, measured as the crow flies: Cass (approx. 5.9 miles away); Battle for the High Ground (approx. 5.9 miles away); Highland County / West Virginia (approx. 7.1 miles away); The Great Raid (approx. 7.1 miles away); a different marker also named Camp Allegheny (approx. 7.1 miles away); West Virginia / Virginia (approx. 7.1 miles away); a different marker also named Camp Allegheny (approx. 7.2 miles away in Virginia); Spirited Artillery Duel (approx. 7.7 miles away).

Other markers no longer nearby. Camp Allegheny 1861-1862 (was approx. 5.9 miles away but has been replaced with another marker now near it); Camp Allegheny (was approx. 5.9 miles away but has been replaced with another marker now near it); War In West Virginia (was approx. 7.1 miles away but has been permanently removed); Staunton-Parkersburg Turnpike (was approx. 7.1 miles away but has been replaced with another marker now near it); The First Campaign (was approx. 7.1 miles

Ewen-Purcell Horn Antenna image. Click for full size.

Photographed by Bernard Fisher, August 7, 2012

2. Ewen-Purcell Horn Antenna

away but has been replaced with another marker now near it).

Also see . . . National Radio Astronomy Observatory. (Submitted on August 11, 2012.)

Credits. This page was last revised on July 23, 2026. It was originally submitted on August 11, 2012, by Bernard Fisher of Richmond, Virginia. This page has been viewed 637 times since then and 51 times this year. Photos: 1, 2. submitted on August 11, 2012, by Bernard Fisher of Richmond, Virginia.