Let aliens know that humans play chess

When the Voyager spacecraft were launched in 1977, included aboard are gold-plated phonograph records containing sounds and images selected to portray the diversity of life and culture on Earth, and are intended for intelligent extra-terrestrials who may find them. The contents of the records were selected for NASA by a committee chaired by Carl Sagan. They assembled a variety of images and sounds, such as those made by surf, wind, thunder and animals including the songs of birds and whales. To this they added musical selections from different cultures and eras, spoken greetings in fifty-five languages, and printed messages from the then US President Carter and United Nations Secretary-General Kurt Waldheim. The collection of 116 images includes diagrams showing physical and mathematical quantities, DNA, human anatomy and reproduction, and the solar system and its planets. Deplorably, no chess game in algebraic notation was included. The images of humanity depict a broad range of cultures; images show humans in portraits as well as in going about their day to day lives. Disappointingly, images of humans playing chess were not considered.