The Arecibo Image If you managed this, you may like to try decoding a real message. The Arecibo message sent in 1974 towards the globular cluster Messier 13 and shown here consisted of 1679 bits - divisible by only 73 and 23, both prime numbers. As well as parts similar to the example above, it contained information about chemistry and even the DNA molecule. You may find the explanation at this website. That signal which was the most powerful signal ever deliberately beamed into space will not arrive at Messier 13 for about 21 to 25 thousand years!