The plaque mounted to Pioneer10 was designed to show when the spacecraft launched, from where, and by what kind of beings. The design was etched in on a gold-anodized aluminum plate attached to the spacecraft’s attenna support struts in a position to help shield it from erosion by interstellar dust. // NASA
In the September issue, David L. Chandler describes how the hunt for extraterrestrials in the universe has changed in the past few decades in “The new search for alien intelligence.” The article describes how other life-forms on distant planets might unintentionally communicate with us, but 40 years ago, talks of ET were just as much as how we might communicate with them.
Prior to the launch of the Pioneer mission in 1972, astronomer and science popularizer Carl Sagan suggested placing a message aboard the spacecraft should it ever encounter any ETs on similar interstellar travel. To his surprise, NASA agreed.
In an essay in the December 1973 issue of Astronomy, Sagan described in detail how he and colleague Frank Drake determined what to etch on the Pioneer plaque. Although the message remains unanswered 40 years later, who knows what the future will bring.