Grote Reber

Biography

Born: December 22, 1911

Died: December 20, 2002

Grote Reber was one of the first radio astronomers, who created an early radio map of the sky in 1944 using a parabolic antenna he built in his suburban Illinois backyard.

Reber was born in Chicago in 1911 and earned a bachelor’s degree at the Armour Institute of Technology (now the Illinois Institute of Technology). After graduation, he worked at various radio manufacturers. By 1937, he was devoting much of his free time and salary to building one of the first radio telescopes.

Reber, a ham radio hobbyist, was fascinated by a study of cosmic radiation by Karl Guthe Jansky, an engineer at Bell Telephone Laboratory. In the early 1930s, Jansky identified a mysterious weak hiss in the radiotelephone transmissions crossing the Atlantic Ocean. He theorized that this noise might be connected with the sun. Using a large antenna, he found that the most intense noise was coming from the center of the Milky Way galaxy, a discovery now known as the diffuse galactic synchroton emission.

Although Bell Labs declined to pursue this discovery, Reber decided to follow Jansky’s lead in his own backyard in Wheaton, Illinois. In 1937, Reber built a parabolic, or curved, radio telescope using sheet metal. With a diameter of 31.4 feet, it could focus radio waves to a point twenty feet above it. Reber’s device amplified cosmic radio signals by a factor of several million, which made it possible for him to record and chart their origins. While generations of early astronomers had developed optical telescopes to chart visible light, he was the first to systematically work outside the visible spectrum.

Drawing the curiosity of his neighbors but little scholarly interest, Reber spent two years charting the night’s sky with his radio telescope. He then published a series of articles in The Astrophysical Journal called “Cosmic Static.” These articles marked the beginning of the field of intentional radio astronomy. In 1944, he created the first contour radio map of the sky, which showed that the center of the Milky Way was the strongest source of radio signals.

Reber’s discoveries proved important after World War II, as radio astronomy emerged as a core tool for mapping distant reaches of the universe. Researchers have built successively larger radio telescopes, including the Very Long Baseline Array, to investigate quasars, pulsars, and the afterglow from the Big Bang—a theory that Reber himself disputed.

Reber worked for the National Bureau of Standards in the late 1940s and then left for Mount Haleakala, Hawaii, where he built a high-altitude observatory. In 1954, he moved to Tasmania, where he lived for the rest of his life. In Tasmania, he mapped the southern sky and studied the cosmos through gaps in the earth’s ionosphere using dipole antennas.

Although he never worked as a professional astronomer, he published in many prestigious journals and earned awards given to those in the highest levels of the field, including the American Astronomical Society’s Henry Norris Russell Lectureship and the Astronomical Society of the Pacific’s Bruce Medal in 1962. A minor planet (6886) was named after him and the annual Grote Reber Medal is now awarded to scientists making significant contributions to radio astronomy.

His original radio telescope is on display at the National Radio Astronomy Observatory, which also houses most of his papers. The University of Tasmania School of Mathematics and Physics runs a museum that preserves his legacy.

Further Reading

Reber papers at National Radio Astronomy Observatory