U.S. Scientists Bounce Radar Signal Off the Sun
Stanford Team Records First Direct Contact Across 186 Million Miles
PALO ALTO, Calif., March 11 — American scientists have achieved another milestone in man’s expanding reach into space, successfully bouncing a radar signal off the sun’s outer atmosphere and recording its return to Earth after a round‑trip journey of some 186 million miles.
The historic contact, made by researchers at Stanford University’s Radioscience Laboratory, marks the first time a man‑made signal has been reflected from the sun. The achievement follows months of analysis to verify faint traces captured on magnetic tape during early‑morning experiments last April 7, 10, and 12.
The radar echo required 17 minutes to complete its trip at the speed of light, a span that dwarfs earlier radar feats. The Army Signal Corps first bounced a signal off the moon in 1946, a journey of less than three seconds, and last year scientists at the Massachusetts Institute of Technology reported radar contact with Venus, a five‑minute round trip from 28 million miles.
Reflection From the Corona
Dr. Von R. Eshleman and Dr. Philip B. Gallagher, coordinators of the Stanford project, said the signal was reflected not from the sun’s visible surface but from its outer corona, a vast envelope of ionized gases extending roughly 500,000 miles into space.
A standard transmitter, operating at about 40,000 watts—comparable to a major short‑wave broadcasting station—was used to send the pulses skyward from the Stanford campus. The returning signals were faint but unmistakable, the scientists said, once months of filtering and verification were complete.
New Tool for Solar Research
The experiment, supported primarily by the Air Force Cambridge Research Center, opens the door to a new era of solar investigation. Radar, long used to probe the moon and nearby planets, may now become a tool for studying the sun’s corona, magnetic fields, and the turbulent region where solar particles stream outward into space.
Researchers believe improved transmitters and more refined techniques could eventually allow continuous monitoring of solar storms, radiation bursts, and other phenomena that affect communications, navigation, and future space travel.
A Step Forward in the Space Race
The accomplishment comes at a time when the United States is striving to match Soviet advances in space science. While the radar experiment is not as dramatic as a rocket launch, it represents a significant technical achievement and adds to the growing body of American research aimed at understanding the environment beyond Earth.
Scientists emphasized that the ability to measure the corona directly will help refine models of the sun’s behavior and may improve predictions of solar disturbances that can disrupt radio transmissions and endanger spacecraft.
Toward Deeper Exploration
With radar now proven capable of reaching the sun, researchers expect the technique to play a larger role in future deep‑space studies. The Stanford team believes that, with stronger transmitters, radar could one day probe even farther into the solar system.
For now, the faint echo from the sun stands as a reminder of how swiftly the boundaries of science are expanding. In the span of just 14 years, radar has reached from the moon to Venus—and now to the sun itself.
Courtesy of The Los Angeles Times February 5, 1960 via Newspapers.com