One evening last year, when his newborn daughter was small enough to hold with one arm, René Heller reached for a book to occupy his mind while he rocked her to sleep. Heller, an astrophysicist at the Max Planck Institutes in Göttingen, Germany, picked up Is Anyone Out There? The Scientific Search for Extraterrestrial Intelligence.
The book is co-authored by Frank Drake, the renowned astrophysicist who came up with an equation to estimate the number of potential alien civilizations in the Milky Way. In it, Drake describes a fake alien transmission he composed in 1960, a series of ones and zeroes that encoded an image, and shared with his contemporaries in the field. Only one person eventually decoded it: a young electrical engineer from New York who had seen Drake’s message in a magazine for amateur code crackers.
Huh, Heller thought. “Why not come up with a modern version?”
Recommended: The Strange Radio Signals Coming From a Nearby Star
So on April 26, 2016, an alien transmission appeared on Twitter. Heller posted a sequence of about 2 million zeroes and ones, binary digits meant to signify radio pulses coming from a pretend civilization 50 light-years from Earth. Radio signals have been considered an efficient means of interstellar communications since the 1960s, when the field of the search for extraterrestrial life, or SETI, was getting off the ground. Unlike other types of electromagnetic radiation, radio waves can pass through gas and dust over large distances of space without being absorbed or interrupted.
In this sequence Heller encoded information about these aliens, like their height, average lifespan, and the nature of their home star system and communication capabilities. He even included a hidden image of a slender, gray creature with long arms and an egg-shaped head. To get to this information, code crackers had to figure out what to do with a bunch of ones and zeroes, which span seven pages in your average text-editing program. Heller gave…