The chances of contacting extraterrestrial civilizations seem poor – Science News, February 24, 1973
The possibility of life … on other planets has stimulated many people’s imaginations…. In the Feb. 9 Nature, James C. G. Walker of Yale University studies the possible parameters of such a search and comes to some pessimistic conclusions.
Update
Walker estimated it could take 1,400 to 14 million years to contact E.T. with the available technology. That’s way longer than researchers have spent listening for alien radio signals and scouring the sky with telescopes and satellites (SN: 11/21/20, p. 18).
Despite the silence, scientists have sent their own messages into the void. In
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