Signals sent in the past

In 1962, the Soviet scientists directed a radio transmitter at Venus and saluted the planet in Morse code. The message was a test run for a new planetary radar to map objects in the solar system.

In 1974, a group of scientists transmitted a radio message toward Messier 13, a cluster of stars about 25,000 light-years away. The image was sent in binary code and depicted a human stick figure, a double-helix DNA structure, a carbon atom model, and a diagram of a telescope.