The Holmdel Horn, a microwave antenna that was used by Arno Penzias and Robert Wilson to detect the cosmic microwave background radiation and provide evidence for the Big Bang theory, is at risk of being lost due to redevelopment plans in the area. The antenna, which was designated a National Historic Landmark in 1989 and is listed as a "historic physics site" by the American Physical Society, was originally built to support Project Echo, a NASA communications program involving the use of inflatable mylar spheres as passive microwave reflectors for intercontinental communication.
However, the active transmission capabilities of satellites made the Echo system obsolete and it was decommissioned in 1968. The Holmdel Horn is 50 feet long with a 20-foot wide opening and a parabolic reflecting surface that focuses incoming radiation onto a cryogenic receiver. In 1965, Penzias and Wilson discovered the persistent hissing noise while working with the antenna and, after collaborating with Princeton physicist Robert Dicke, were able to confirm the Big Bang theory.
The antenna is located in Holmdel, New Jersey and the property, which was originally owned by Bell Labs, is currently being sold by Nokia.
Story here by Larry Faltz, a retired physician and member of Westchester (NY) Amateur Astronomers in Sky & Telescope 9th Dec 2022 :-
https://skyandtelescope.org/astronom...ng-is-at-risk/
