Radio Telescopes’ Time in the Sun Has Passed
By Joshua PartlowApril 12, 2004Email the author
The white paint on the abandoned research buildings is peeling. Overgrown grass entangles a chain-link fence that displays two ominous metal signs: “Government property — No trespassing.”
And the two radio telescopes — their towers rising more than 100 feet, with massive parabolic dishes that trolled the galaxy for evidence of exploded stars, hydrogen clouds, masers, quasars, black holes and a comet that crashed into Jupiter — are rusted now and used only by nesting ospreys.
Here at the Maryland Point Observatory, tucked amid towering oak trees in a corner of Charles County along the Potomac River, the Navy once conducted groundbreaking work in radio astronomy. The telescopes were built after World War II, and for a time they were among the largest, most powerful machines in the world for detecting radiation emitted by celestial bodies.
That time is gone. The telescopes have not been used since 1994, when astronomers relied on them to study the collision of the comet Shoemaker-Levy 9 with Jupiter, the first observed collision of two solar system bodies. By then, the technology had become mostly obsolete, surpassed by larger, more sophisticated telescopes that often worked in unison to multiply their powers of observation.
Since 2002, the 23-acre site has been owned by the Bureau of Land Management, which plans to dismantle the telescopes and convert the property into something else, perhaps an environmental education center, officials said. The bureau has hired an engineering firm but has not set a date to begin the overhaul.
“It’s kind of sad in a way, but progress is progress, I guess,” said Edward McClain, 82, former head of the radio astronomy branch of the Naval Research Laboratory who helped pick the site and oversaw construction of its first telescope, 84 feet wide, in 1958.
Back then, it was the largest steerable radio telescope in the United States. It was intended to study radiation from the sun and moon and to pinpoint optically invisible phenomena in space. The Navy picked southwestern Charles County because of its isolation — there would be none of the radio interference from Washington’s National Airport, more than 40 miles away, that plagued its facility in the District. It was so remote that, McClain said, he would spend the lonely drive to work testing how fast it took his white Plymouth to reach 100 mph.
The second telescope, larger in diameter by a foot, followed in 1965, offering the team of about 20 scientists even higher resolution to study the heavens. The telescopes, fixed in position, would use the rotation of the earth to sweep the sky, and the strength of the signal would be marked on long scrolls of paper in the control room.
“That was before the time when we had anything digital,” said Robert Hobbs, 66, who worked at Maryland Point in the late 1960s. “We used rulers and so forth to measure how intense the radiation was.”
The field of radio astronomy came about primarily by accident, historians have said. During the 1920s, radio communication across the oceans was frequently hindered by staticlike interference. Bell Telephone Laboratories assigned a young engineer named Karl Jansky to investigate, and he set up a large, steerable antenna in New Jersey. In 1932, Jansky found that thunderstorms contributed to the interference but also that electromagnetic waves emanating from space played a role. After World War II, the field expanded rapidly, and radio telescopes were used to help map the galaxy, find exact coordinates of the earth’s poles and meridians and measure other celestial bodies that were out of reach or obscured from the view of optical telescopes.
“Radio astronomy is enormously important,” said James Moran, a professor of astrophysics at Harvard University. “It’s given us the best evidence for the existence of black holes at the centers of galaxies.”
Scientists searching for signs of alien life have also found radio telescopes to be the tool of choice. Last month, the Search for Extraterrestrial Intelligence Institute received a $13.5 million gift from Microsoft co-founder Paul G. Allen to start construction on the Allen Telescope Array, a project that will use 350 radio telescopes in a remote region of Northern California to look for signals from any potential neighbors in space.
Maryland Point’s scientists were not explicitly looking for alien friends, but some said they kept open the possibility of hearing a voice from beyond.
“If we got Morse code from another galaxy, we would have probably passed out and then run out and told everybody about it,” Hobbs said. “We were all interested, but we didn’t have the funding. Our science was considered far out, but looking for extraterrestrial life was probably a bit too off the wall for the Navy.”
He and other astronomers said the Navy was interested in using the telescopes to improve the knowledge of geographic positioning on Earth to assist navigation. In the 1970s, much of the research at the observatory focused on identifying molecular clouds, said Kenneth Johnston, a former employee there and now scientific director at the U.S. Naval Observatory in Washington.
“Before that, people didn’t know molecules existed in space in dark clouds,” he said.
Maryland Point also launched the first project to coordinate with other telescopes in different locations to increase the accuracy of their observations. Using this method, the astronomers could study the energy from quasars, or “qausi-stellar radio sources,” the black holes at the center of galaxies, Johnston said. “It looked like they were expanding faster than the speed of light . . . and everybody thought you could win a Nobel Prize studying this,” he said.
By the early 1980s, military funding for the observatory was cut back, said Cornell Mayer, head of the radio astronomy branch of the Naval Research Laboratory, who took over after McClain. “Along the line,” he said, “the Pentagon lost interest in research. ‘We know what you did for us yesterday — what are you going to do for us today?’ That was their line.”
Meanwhile, other, more powerful, telescopes were built around the world, and Maryland Point began to lose its relevance, the scientists said. When the Naval Research Laboratory no longer wanted the observatory, the property was passed to the General Services Administration and then the Bureau of Land Management.
On a tour of the property last week, Gary Cooper, a regional manager for the bureau, said that his agency would dismantle the telescopes and some of the outbuildings before finding another use for the scenic riverfront property.
When they take down the telescopes, he said, pointing at the rusted 84-footer that slumped toward the ground and the vast expanse surrounding it, “we’re not going to bother anyone out here. Just the ospreys.”
Joseph Zilincar and Gary Cooper of the Bureau of Land Management visit the Maryland Point Observatory in Charles County, where the Navy studied the skies.