In November 1974, the Arecibo Telescope in Puerto Rico fired a 1679-bit radio message toward the globular cluster Messier 13 in the constellation Hercules. 1679 is the product of two prime numbers, suggesting (hopefully) that the bits might be arranged in a 23 × 73 grid:

This gives some basic information about our civilization: the numbers 1-10; a description of the composition and structure of DNA; an image of a man, together with information about his size and the human population; a picture of the solar system, indicating which planet had sent the message; and an image of the Arecibo telescope.
In August 2001, a similar 23 × 73 grid was discovered impressed in a wheat field near the Chilbolton radio telescope in Hampshire:

Silicon has been added to the table of atomic numbers that make up DNA; the number of nucleotides has been changed; the population value, solar system information, and transmitter diameter have changed; and a squat creature with a bulbous head has replaced the man. The message also bears a representation of a crop circle that had appeared in the same field a year earlier.
Had aliens responded to our message? The SETI Institute Online wrote, “This is highly improbable. There is no evidence to suggest an other-than-earthly origin for these graphics.”



