Forty years ago this month, Planet Earth said hello to the cosmos with the launch of the two Voyager probes that used gravity to swing from world to world on a grand tour of the solar system. Each bore a two-sided, 12-inch, gold-plated copper “Golden Record” of sights and sounds from Earth and its people — and a stylus to help play the record. Documents that Changed the World: Listen: Voyager’s “Golden Record,” 1977 About 20 billion kilometers (about…
August 23, 2017