The Pioneer plaques are a pair of gold-anodized aluminium plaques which were placed on board the 1972 Pioneer 10 and 1973 Pioneer 11 spacecraft, featuring a pictorial message, in case either Pioneer 10 or 11 is intercepted by extraterrestrial life. The plaques show the nude figures of a human male and female along with several symbols that are designed to provide information about the origin of the spacecraft.
The Pioneer 10 and 11 spacecrafts were the first human-built objects to achieve escape velocity from the Solar System. The plaques were attached to the spacecraft's antenna support struts in a position that would shield them from erosion by stellar dust.
The original idea, that the Pioneer spacecraft should carry a message from mankind, was first mentioned by Eric Burgess when he visited the Jet Propulsion Laboratory in Pasadena, California, during the Mariner 9 mission. He approached Carl Sagan, who had lectured about communication with extraterrestrial intelligences at a conference in Crimea.
Sagan was enthusiastic about the idea of sending a message with the Pioneer spacecraft. NASA agreed to the plan and gave him three weeks to prepare a message. Together with Frank Drake he designed the plaque, and the artwork was prepared by Sagan's then-wife Linda Salzman Sagan.
Both plaques were manufactured at Precision Engravers, San Carlos, California.
Physical properties
Material: 6061 T6 gold-anodized aluminum
Width: 229mm (9 inches)
Height: 152mm (6 inches)
Thickness: 1.27mm (0.05 inch)
Mean depth of engraving: 0.381 millimeters (381µm) (0.015 inch)
Mass: approx. 0.120 kilograms (12 g) (4.2oz)
