Arecibo messageThe Arecibo message is an interstellar radio message carrying basic information about humanity and Earth that was sent to the globular cluster Messier 13 in 1974. It was meant as a demonstration of human technological achievement, rather than a real attempt to enter into a conversation with extraterrestrials. The message was broadcast into space a single time via frequency modulated radio waves at a ceremony to mark the remodeling of the Arecibo Telescope in Puerto Rico on 16 November 1974.
Voyager Golden RecordThe Voyager Golden Records are two identical phonograph records one of each which were included aboard the two Voyager spacecraft launched in 1977. The records contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form who may find them. The records are a time capsule. Although neither Voyager spacecraft is heading toward any particular star, Voyager 1 will pass within 1.
Communication with extraterrestrial intelligenceThe communication with extraterrestrial intelligence (CETI) is a branch of the search for extraterrestrial intelligence (SETI) that focuses on composing and deciphering interstellar messages that theoretically could be understood by another technological civilization. The best-known CETI experiment of its kind was the 1974 Arecibo message composed by Frank Drake.
Time capsuleA time capsule is a historic cache of goods or information, usually intended as a deliberate method of communication with future people, and to help future archaeologists, anthropologists, or historians. The preservation of holy relics dates back for millennia, but the practice of preparing and preserving a collection of everyday artifacts and messages to the future appears to be a more recent practice. Time capsules are sometimes created and buried during celebrations such as a world's fair, a cornerstone laying for a building, or at other ceremonies.
Search for extraterrestrial intelligenceThe search for extraterrestrial intelligence (SETI) is a collective term for scientific searches for intelligent extraterrestrial life, for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other planets. Scientific investigation began shortly after the advent of radio in the early 1900s, and focused international efforts have been ongoing since the 1980s. In 2015, Stephen Hawking and Israeli billionaire Yuri Milner announced the Breakthrough Listen Project, a $100 million 10-year attempt to detect signals from nearby stars.
