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 them about six weeks.
The first correct response appeared in his inbox the next day. Over the next several weeks, Heller received more than 300 replies to his call, including the right answer, the wrong answer, questions, pleas for hints, and even a few insults. (“This is one trait of the internet,” he said dryly. “You put out something and people just send an email to you and insult you.”) A spoiler showed up on Reddit. When the window for submissions closed, Heller had 66 correct responses from individuals or teams.
Most of the responses came from North America’s East Coast and Western Europe—not surprising, Heller says, considering the call was in English. They included scientists, software engineers, and, among others, two high-school students. Half had a bachelor’s or doctorate degree in mostly scientific fields. The vast majority were men.
To find the secret image, the string of ones and zeroes should be treated as black and white pixels and arranged in a certain way, so that the alien pops into view. You can do it yourself: copy and paste the sequence, found here, into a text editor, adjust the width of the window so that the first line is made up entirely of ones, and the first zero starts the second line. Zoom way out, and start scrolling down. Soon enough, the ghostly shape of a two-dimensional lanky alien should blur into existence before your eyes.
Deciphering the non-visual information, like numbers meant to signify the imaginary aliens’ height and lifespan, is a little trickier, and involves a good deal of math, an understanding of how binary code works, and knowledge of values known as cosmological constants. (For all the details, check out Heller’s paper on the experiment here).
Heller said the enthusiastic response to the call surprised him: “I would have expected maybe five or 10 of my Twitter followers, who are mostly astrophysicists or people who are interested in astrophysics, to maybe respond.”
The decoders of a real alien message from afar, should one ever reach Earth, may not necessarily need to be astrophysicists or linguists, as science fiction has shown. They could be computer programmers or hackers. Heller’s digital experiment illustrates the advantage of applying people from a number of disciplines to a single problem. The method is also in line with one of the mission statements of SETI. “A confirmed detection of extraterrestrial intelligence should be disseminated promptly, openly, and widely through scientific channels and public media,” states the SETI Institute in its protocol for what should happen when intelligent life is detected. A few months ago, when telescopes observed mysterious dimming in the brightness of a distant star—which some say could be caused by some kind of alien structure blocking the light—scientists live-tweeted about it.