Audio Guide：

The probes launched in the 1970s, including Pioneer 10 and 11, and Voyager 1 and 2, carried audio-visual discs in the hope of encountering extraterrestrial civilizations. In 1974, astronomers used a radio telescope, the Arecibo Observatory, to transmit a message to the globular cluster M13. However, due to the remote distance, the message will not arrive before the year 22,000.

Use the texts and images on display and the interactive software to find out what messages humans have sent to outer space.