The 1974 Arecibo Message: A Deliberate Broadcast to Extraterrestrials and Its Ongoing Legacy

To the point

About 25 years after a historic gesture, during the dedication of a major Arecibo upgrade, people sent a deliberate three-minute radio message from the telescope toward the globular cluster Messier 13 to share basic facts about humanity and life and to demonstrate the transmitter’s power, encoded at 2380 MHz as 1,679 binary bits forming a 23-by-73 image, with the effort led by Frank Drake, Richard Isaacman, Linda May, James C.G. Walker and Carl Sagan contributing, while the telescope continues to listen through programs like Phoenix and Serendip, alongside the Pioneer 10 copper plate and later transmissions from a Russian telescope and plans by Encounter2001, underscoring the ongoing quest to find intelligent life beyond Earth.