Pioneer plaque
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 plaques were attached to the spacecraft's antenna support struts in a position that would shield them from erosion by interstellar dust.
The original idea, that the Pioneer spacecraft should carry a message from mankind, was first mentioned by Eric Burgess[2] when he visited the Jet Propulsion Laboratory in Pasadena, California, during the Mariner 9 mission.
[5] At the top left of the plaque is a schematic representation of the hyperfine transition of hydrogen, which is the most abundant element in the universe.
The spin-flip transition of a hydrogen atom's electron has a frequency of about 1420.405 MHz, which corresponds to a period of 0.704 ns.
dates back to a printing error in the original article "A Message from Earth" which is the primary source for many of the copies of the engraving.
[8] Originally Sagan intended the humans to be shown holding hands, but soon realized that an extraterrestrial might perceive them as a single creature rather than two organisms.
It has been claimed that Sagan, having little time to complete the plaque, suspected that NASA would have rejected a more intricate drawing and therefore made a compromise just to be safe.
[9] Sagan said that the decision to not include the vertical line on the woman's genitalia (pudendal cleft) which would be caused by the intersection of the labia majora was due to two reasons.
[10] According to the memoirs of Robert S. Kraemer, however, the original design that was presented to NASA headquarters included a line which indicated the woman's vulva,[11] and this line was erased as a condition for approval of the design by John Naugle, former head of NASA's Office of Space Science and the agency's former chief scientist.
Fourteen of the lines have corresponding long binary numbers, which stand for the periods of pulsars, using the hydrogen spin-flip transition frequency as the unit.
The pulsar map and hydrogen atom diagram are shared in common with the Voyager Golden Record.
A small picture of the spacecraft is shown, and the trajectory shows its way past Jupiter and out of the Solar System.
Both had broad and flattened noses, and the woman was given epicanthial folds to resemble East Asian people.
[18] According to astronomer Frank Drake, there were many negative reactions to the plaque because the human beings were displayed naked.
[21] In contrast, in another letter to the same newspaper, a person was critical of the prudishness of the people who found depictions of nudity to be obscene.
