Before revision: The Pioneer plaques are a pair of gold-anodized aluminum plaques that 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 intelligent extraterrestrial life.
After revision: The Pioneer plaques are a pair of gold-anodized aluminium plaques that 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 intelligent extraterrestrial life.