mountain profile Institute for Astronomy University of Hawaii

Radio Astronomy

Maintained by CGWW

Hawai`i played a minor role in the early days of radio astronomy. After the discovery of cosmic radio emissions by Karl Jansky in 1931, one of the first to take up the scientific investigation of these emissions was Grote Reber with a radio telescope in his backyard in Wheaton, Illinois.  In 1951 Reber came to Hawai`i to take advantage of a unique geophysical condition.  By placing his antenna atop 10,000-foot Haleakala on the island of Maui, he hoped to use the ocean as a reflector so that the antenna received both the direct signal from a cosmic radio source and the signal reflected from the ocean, forming a “Lloyd's Mirror” type of interferometer. His antenna was built on a circular track so that it could be rotated in any direction.

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A portion of Grote Reber’s antenna structure showing the circular track upon which it rotates. In the background is Red Hill, the summit of Haleakala, and some remaining WW2 structures. 1955.

Students at the Maui Technical School (later Maui Community College) constructed the welded steel and wood truss support system. Reber was disappointed with his results. In his research report on Haleakala observations, Reber (19) states that:, "In addition to the natural limitations imposed by the ionosphere (it is opaque at many wavelengths), a large amount of man-made electrical disturbance was encountered. This was due to the exposed position of the observer and the fact that the technique required looking at the horizon. The two main centers of disturbance were the local industrial area of Kahului-Puunene at a distance of 20 miles NNW, and Honolulu-Pearl Harbor at a distance of 120 miles WNW. Consequently the quadrant from north to west was frequently unusable. Radio astronomy observations should not be located atop high mountain peaks."

He was still on Maui in 1955 when I first investigated Haleakala as a possible solar observatory site. Soon thereafter Reber left for Tasmania, where he continued his researches. In 1957 the antenna structure collapsed under the weight of heavy ice deposited by a storm, a not-unusual condition on Haleakala where supercooled clouds may pass over the mountain and cover exposed structures and wires with several inches of ice.

After many years of productive research in Tasmania and other places, Reber died in 2002. He is revered by his friends and associates as “The Father of Radio Astronomy”. As a memorial to him, his Australian associates have arranged to encase small amounts of his ashes in metal cases to be mounted with plaques at various radio telescopes around the world. One has been placed on the concrete block-house on Haleakala where he had worked.

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