I read this week's XKCD and learned a fun new fact about the first contact with the moon.
A replica of the ball that they mention in the comic is shown below:
My question from this is:
Since this event, have we ever sent a payload with the express purpose of screaming into the void that we were there? I would including anything from "Apollo planting a flag on the moon" to "Elon musk launching a Telsa into orbit around the sun". What are some of the more surprising non-scientific payloads that have been sent into space with a focus on things left behind?
Is this too open-ended of a question?