Communications: TV Beacons in Space

The ultrahigh-frequency television stations that are gradually spreading across the country may be reaching an unexpected audience. UHF transmissions, says Institute of Electrical and Electronics Engineers President Bernard Oliver, may have already provided the first evidence to extraterrestrial civilizations that intelligent, or anyway TV-producing life exists on earth.

Sweeping the Universe. Unlike low-frequency radio waves, which are reflected back by the earth's ionosphere, UHF transmissions continue traveling in a straight line out into the farthest reaches of space. And unlike standard television waves, which penetrate into space but tend to be drowned out by cosmic radiation of about the same...