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History of Radio Astronomy
Radar advances
World War II brought radar which had much more sensitive directional receivers. Radar works by sending out short waves to be reflected back from a target. In early 1946 the United States Army bounced radar waves back from the moon. This was soon repeated by many other countries. In 1945, J. S. Hey and G. S. Stewart observed radar echoes during the daytime. The next year three men at Jodell Bank in England investigated these echoes and found that they were due to meteor showers. These valuable results quickly led to great improvements in short-wave receivers and the construction of radio telescopes in England, Australia, and the United States. Radio telescopes receive extremely weak signals from a tiny area in the sky and amplify them so that their intensities can be recorded.
Page 1: Birth of radio astronomy
Page 2: Experimenting with wave lengths
Page 3: Radar advances
The Astronomy Interactive Network is a web site for the
1998 Thinkquest contest
created by Rand, Noah and Kim.