Lucky Bounce
We see the Moon not because it makes its own light, but because it reflects sunlight. And in the 1950s and early 60s, the Defense Department used the Moon to reflect another form of energy: radio waves. That allowed the Pentagon to stay in touch with American forces around the world.
In fact, the U.S. Navy bounced the first voice transmission off the lunar surface 50 years ago today. The voice belonged to James Trexler, a Navy engineer and a developer of "Operation Moon Bounce."
The Pentagon was interested in the Moon because radio communications at the time could be fickle. The Navy stayed in touch with its fleet by bouncing radio signals off a layer of Earth's atmosphere known as the ionosphere. But storms on the Sun could disrupt the ionosphere, leaving American forces in the dark.
The Navy had started bouncing radar signals off the Moon a couple of years earlier. It found that the reflected signals were much stronger than expected. That led to the hope that the Moon might serve as a radio relay station.
After the 1954 test, the Navy developed an entire network that used the Moon as a relay station for voice, teletype messages, and even pictures. The system remained in use until artificial satellites began to provide a better alternative.
The Moon is well up in the southwest at nightfall. The bright star Spica is to its right. Spica sets around midnight, with the Moon following about a half-hour later.
Script by Damond Benningfield, Copyright 2004
For more skywatching tips, astronomy news, and much more, read StarDate magazine.
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