File:Arecibo message.svg

The formulas for the sugars and bases in the nucleotides of DNA.

The numbers one (1) through ten (10)

The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA).

The number of nucleotides in DNA, and a graphic of the double helix structure of DNA.

A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth.

A graphic of the Solar System.

Transverse cross-section (parabolic) of the transmitting antenna dish (paraboloid) of the Arecibo radio telescope.

Demonstration of the operation of a paraboloid dish (specifically Arecibo observatory's transmission dish, although the principle holds generally):

For reception, parallel or near-parallel rays are reflected to a focus in front of the center of the dish, where an antenna element, possibly with waveguide, can be positioned to receive a signal (in the case of Arecibo, a radioastronomy or SETI signal).

For transmission, as the message itself would have been sent, the signal originates from a transmitter at the focal point, reflects off the dish, and it sent forth in parallel, to be aimed with a comparatively narrow angular direction towards the intended recipient (in this case, the area of cluster M13, although no presumptions were made as to life existing there or being able to receive, as the message was more ceremonial in nature).