---
title: "Operation Moonwatch"
chunk: 1/2
source: "https://en.wikipedia.org/wiki/Operation_Moonwatch"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:15:22.984256+00:00"
instance: "kb-cron"
---

Operation Moonwatch (also known as Project Moonwatch and, more simply, as Moonwatch) was an amateur science program formally initiated by the Smithsonian Astrophysical Observatory (SAO) in 1956. The SAO organized Moonwatch as part of the International Geophysical Year (IGY). Its initial goal was to enlist the aid of amateur astronomers and other citizens who would help professional scientists spot the first artificial satellites. Until professionally staffed optical tracking stations came on-line in 1958, this network of amateur scientists and other interested citizens played a critical role in providing crucial information regarding the world's first satellites.

== Origins of Moonwatch ==
Moonwatch's origins can be traced to two sources.  In the United States, there was a thriving culture of amateur scientists including thousands of citizens who did astronomy for an avocation.  During the Cold War, the United States also encouraged thousands of citizens to take part in the Ground Observer Corps, a nationwide program to spot Soviet bombers.  Moonwatch brought together these two activities and attitudes, melding curiosity and vigilance into a thriving activity for citizens.  Moonwatch, in other words, was an expression of 1950s popular culture and fixed properly within the context of the Cold War.
Moonwatch was the brainchild of Harvard astronomer Fred L. Whipple.  In 1955, as the recently appointed director of the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, Whipple proposed that amateurs could play a vital role in efforts to track the first satellites. He overcame the objections of colleagues who doubted ordinary citizens could do the job or who wanted the task for their own institutions. Eventually, Whipple carved out a place for amateurs in the IGY.

== Moonwatch's members ==
In the late 1950s, thousands of teenagers, housewives, amateur astronomers, school teachers, and other citizens served on Moonwatch teams around the globe.  Initially conceived as a way for citizens to participate in science and as a supplement to professionally staffed optical and radio tracking stations, Moonwatchers around the world found themselves an essential component of the professional scientists’ research program.  Using specially designed telescopes, hand-built or purchased from vendors like Radio Shack, scores of Moonwatchers nightly monitored the skies.  Their prompt response was aided by the extensive training they had done by spotting pebbles tossed in the air, registering the flight of moths, and participating in national alerts organized by the Civil Air Patrol.
Once professional scientists had accepted the idea that ordinary citizens could spot satellites and contribute to legitimate scientific research, Whipple and his colleagues organized amateurs around the world. Citizens formed Operation Moonwatch teams in towns and cities all around the globe, built their own equipment, and courted sponsors. In many cases, Moonwatch was not just a fad but an expression of real interest in science. By October 1957, Operation Moonwatch had some 200 teams ready to go into action, including observers in Hawaii and Australia.

== How Moonwatch worked ==

Whipple envisioned a global network of specially designed instruments that could track and photograph satellites. This network, aided by a corps of volunteer satellite spotters and a computer at the MIT Computation Center, would establish ephemerides – predictions of where a satellite will be at particular times. The instruments at these stations were eventually designed by Dr. James G. Baker and Joseph Nunn and hence known as Baker-Nunn cameras. Based on a series of super-Schmidt wide-angle telescopes and strategically placed around the globe at 12 locations, the innovative cameras could track rapidly moving targets while simultaneously viewing large swaths of the sky.
From the start, Whipple planned that the professionally staffed Baker-Nunn stations would be complemented by teams of dedicated amateurs. Amateur satellite spotters would inform the Baker-Nunn stations as to where to look, an important task given that scientists working on the Vanguard program likened finding a satellite in the sky to finding a golf ball tossed out of a jet plane.  Amateur teams would relay the information back to the SAO in Cambridge where professional scientists would use it to generate accurate satellite orbits. At this point, professionals at the Baker-Nunn stations would take over the full-time task of photographing them.

== During the IGY ==