Each of the two Voyager spacecraft, which are now well beyond the orbit of Neptune, carries onboard a gold-plated phonograph record that bears pictographs showing how to play them using simple (by human standards) electrical technology. Each “Golden Record” contains about two hours of sounds that can be heard on Earth, such as falling rain, thunder, bird and animal calls, human speech, and all kinds of music. If an intelligent species found one of the Voyager probes, it might be possible for them to learn something about humans and about Earth—a distant, friendly greeting from us to them.