DTM Archives Acquire John Firor’s Radio Astronomy Research Notebooks
Sixty-year-old research notebooks recently acquired by the DTM archives are shedding new light on the Department's pioneering research in radio astronomy in the 1950s.
The notebooks and research files, which belonged to former DTM scientist John W. Firor, were discovered in 2015 inside a storage closet at NOAA's Office of Coast Survey in Silver Spring, Maryland. They were transferred to the DTM Archives, where they have been recently incorporated into the Radio Astronomy Program Records.
A guide to the collection is available here.John W. Firor working on the Precise Position Apparatus, one of several radio telescopes built at DTM's River Road site, ca. 1959.
Firor, who joined the DTM staff in 1953, was a physicist whose graduate work at the University of Chicago had focused on cosmic-rays. At DTM he became part of a fledgling radio astronomy group assembled by director Merle Tuve. Radio astronomy was still in its infancy and Tuve saw getting into the field as a natural extension of DTM's thirty years of experience in studying the upper atmosphere using radio waves. Scientists in the new DTM program turned their attention to the recently-discovered "radio stars" and to radio emissions from the Sun, as well as mapping the structure of the Milky Way galaxy using neutral hydrogen.
To pinpoint the locations of active solar radio sources, Firor and colleagues constructed a special antenna consisting of thirty pairs of corkscrew-shaped elements tuned to 328 MHz. The helix array stretched in a 2000-foot line across farmland leased by DTM in rural Seneca, Maryland. The new instrument soon detected areas of enhanced radiation moving across the solar disk as the Sun rotated. Another DTM radio telescope on the same site revealed radio emissions from Jupiter in 1955—a discovery later recognized as the first detection of a planetary magnetic field. Today, a Maryland state highway historical marker on River Road marks the observing site.Left: A page from Firor's notebook describing elements of the helix array, ca.1956. Right: Part of the helix array used for solar radio astronomy studies at DTM's River Road site, ca. 1955.
Firor left DTM in 1961 to lead the High Altitude Observatory (HAO) from 1961 to 1968. He was the Director of the National Center for Atmospheric Research (NCAR) from 1968 to 1974, and founded the Solar Physics Division of the American Astronomical Society.
John William Firor Jr. was born in 1927, in Athens, Georgia, the son of William Firor, a professor of agricultural economics at the University of Georgia. Firor studied engineering at the Georgia Institute of Technology but changed his major to physics after spending time at the Los Alamos National Laboratory, where he guarded radioactive materials and talked with scientists involved in the Manhattan Project. He received his Ph.D. in physics from the University of Chicago in 1954.
Firor was an early voice on the topic of human-induced climate change. His book, The Changing Atmosphere: A Global Challenge, was published in 1990, and has been translated into nine languages. Firor was an eloquent and skilled speaker who made science clear to lay audiences, and was often called upon to testify before Congressional committees.
His research interests included climate change, the economics of climate change, sustainable development, and the use of scientific information in the public policy process. He participated in expeditions to observe solar eclipses in New Guinea, Brazil, and Kenya, and wrote many research papers on cosmic rays, radio sources in the universe, the Sun's atmosphere, and solar flares.
—Shaun Hardy and Mary Ferranti