The Benefits and Harms of Transmitting Into Space

Deliberate and unintended radio transmissions from Earth propagate into space and could be detected by extraterrestrial watchers over interstellar distances. However, attempts to date at sending messages to extraterrestrial intelligence (METI) have much lower chances of detection than background radio noise from current communication technology on Earth. METI broadcasts are usually transient and are several orders of magnitude less powerful than other terrestrial sources such as astronomical and military radars, which emit the most detectable leakage signals. METI at this level does not pose any measurable risk to Earth or humanity.