FOR nearly 50 years, the Search for Extraterrestrial Intelligence (SETI) has scanned the heavens for signs of alien life. At the same time, scientists have painstakingly crafted messages to send in reply. When NASA launched its Voyager missions in 1977, for example, both spacecraft carried audio recordings depicting the diversity of life and culture on Earth.
But those messages have never truly represented all of humanity. On 15 May that will change as the . As yet there are no plans to transmit these into space, but…
