This is the binary message we sent out to aliens 38 years ago

Illustration for article titled This is the binary message we sent out to aliens 38 years ago

This is the Arecibo message, created by legendary astronomer Frank Drake in 1974. Of course, it's still competing with all the TV and radio signals we're constantly emitting...but at least this interstellar communication has a touch of dignity, you know?

Illustration for article titled This is the binary message we sent out to aliens 38 years ago

The message was created for the dedication of the Arecibo Observatory in Puerto Rico, which remains the most powerful radio telescope in the world. (It was also used as the filming location for the climax of GoldenEye, so really it's just chock full of feathers in its metaphorical cap.) To see the message more clearly, click on the image up top to expand.

Designed by Frank Drake - the inventor of the eponymous Drake equation, which estimates the number of alien civilizations in the universe - with the help of Carl Sagan and other luminaries, the message was beamed at a frequency of 2380 megahertz at a power of 1000 kilowatts towards the globular cluster M13, which was one of the nearest densely packed parts of the sky available when the observatory was dedicated.

The message is just 210 bytes of information organized onto a grid of 1679 binary digits. That particular number was chosen because it's semiprime, meaning it is the product of two prime numbers, in this case 23 and 73. That means any civilization that received the message would know the grid would have to be 23 by 73, and only one of the two possible arrangements presents intelligible information. NASA provides a rundown of what's on the message:

The above message gives a few simple facts about humanity and its knowledge: from left to right are numbers from one to ten, atoms including hydrogen and carbon, some interesting molecules, DNA, a human with description, basics of our Solar System, and basics of the sending telescope.

Of course, we can't expect to hear anything back in even the remotely near future - since M13 is 25,000 light-years away, the earliest we'll be hearing back from any alien civilizations is the year 51974...give or take a millennium or two.





We can never contact an extraterrestrial civilization less advanced than we are because they would not be capable of contact. We just barely are; the ability to communicate over interstellar distances was developed within living memory. So, anyone we find will be equal to or more advanced than we are. Human civilization is roughly 5,000 years old, and the universe is something like 15 billion years old (yes, I know it's 13.75, but let's round off). So, the universe is about 3 million civilizations old. Let's guess that the first million was taken up with planets cooling and whatnot. So, the odds that we will encounter a civilization at the same state of development as us is then 1 in 2 million, while the odds of encountering a more advanced civilization are 1,999 999 in 2 million. Chances are anyone who receives this message will be vastly more advanced than we are.

Imagine you're walking along the beach on a nice sunny day. Out in the ocean there's a smarter-than-average jellyfish who has decided to search for extra-ocean intelligence. He's transmitting a signal in the only way he knows how to communicate; he's releasing pheromones into the water. As your shadow falls over the jellyfish he can't even begin to conceptualize what you are.

Meanwhile you don't notice the jellyfish at all, and even if you did you wouldn't notice that he's trying to communicate. And even if you're a marine biologist who knows about jellyfish pheromones you wouldn't know what they mean; the jellyfish is just to primitive.

The gulf between aliens and us is probably at least as great as between us and jellyfish. It could also be greater; for jellyfish substitute bacterium. If anyone out there receives this signal it will be like the jellyfish pheromones are to us: too primitive to understand.

[reposted from a related article]