Millstone Hill Antenna

The Millstone Hill Antenna is a fully steerable radio dish spanning 46 meters across, located at MIT Haystack Observatory in Westford, Massachusetts. It transmits and receives signals to observe the upper atmosphere and track how it changes.

The antenna was originally built in 1963 at Sagamore Hill Radio Observatory in Hamilton for atmospheric research. In 1978, the entire dish was relocated to its current site at Millstone Hill.

The facility connects with other incoherent scatter radar stations from Greenland to Peru, forming a chain for comprehensive atmospheric research programs.

The antenna sits on a large campus in a rural area, so arriving by car is the most practical approach. Visitors can view the structure from outside, offering a clear sense of its impressive scale.

Only two dishes of this specific type remain worldwide, with the other located at Stanford University in California. This rarity makes the Millstone Hill Antenna an important survivor of early radar research technology.

Part of: Millstone Hill Observatory

GPS coordinates: 42.61740,-71.49100

Latest update: December 14, 2025 11:06