What is Pioneer plaque?
{{nosources|date=June 2009}} [[File:Pioneer_plaque.svg|thumb]] The '''Pioneer plaques''' were a pair of plaques that were launched into deep space on [[Pioneer 10]] and [[Pioneer 11]], and information about our place in the [[Milky Way|galaxy]] are drawn in case any aliens find it. The same [[image]] is on both plaques. The image is made up of many parts. There is a [[drawing]] of a [[nude]] [[human]] [[female]] and a nude human [[male]]. Behind them is the Pioneer spacecraft to compare their sizes. There is a diagram of the change in spin of the electron of a [[hydrogen]] particle. This diagram is meant to set up a universal unit of length and a universal unit of time for the rest of the image. There is a [[map]] of our [[solar system]] showing a spacecraft leaving the third planet, [[Earth]]. There have been negative reactions about the [[arrow]] showing the trajectory of the spacecraft. Alien species may not understand the human concept of a line and arrow. There is pattern of lines that looks like a star burst design. This is a map. There are 15 lines. 14 of the lines have a long [[binary]] number engraved along it. The binary numbers are distances. The distances are not in [[meter]]s or [[kilometer]]s, but in the universal unit of distance given by the hydrogen particle diagram. The 14 lines give the distance from the [[sun]] to 14 [[pulsar]]s. The 15th line gives the distance from the sun to the center of the [[galaxy]]. [[Category:Pioneer program]]