Silicon Disk.

ID: 541 ~ Source: Smithsonian National Air and Space Museum. “Apollo 11 Goodwill Disc.” Smithsonian National Air and Space Museum, Accessed November 2018, https://airandspace.si.edu/exhibitions/out-of-this-world/online/1969/GoodwillDisc.cfm.
This file appears in: Sprague Electric and the Space Race
Silicon Disk.

The disk contained the Apollo 11 goodwill messages. It included messages from 73 countries around the world and the major world powers at the time. The disk was left in the moon by American astronauts on the Moon’s Sea of Tranquility.

This file appears in: Sprague Electric and the Space Race

By Roberto Castillo
In the Moon’s Sea of Tranquility, there is a small object, no bigger than a fifty-cent coin. It is made out of silicon and is in the shape of a disk. It may seem unimportant to the untrained eye this silicon disk contains the Apollo 11 Goodwill…