The Alien Gold Plate

There is a small planet some 150 trillion miles from Earth and if someone on Earth sends a message to this planet at approximately 40,000 miles per hour, it will take 500,000 years to deliver it. For all of the obvious reasons, including one that the sender doesn't even know for sure the planet is there; there will not be a lot of communication taking place. But in the loosest of terms communication is possible, but it requires a sender who will be extinct hundreds of thousands of years before the message is delivered, doesn't know who they are sending it to, and a recipient who has no idea a message is in route and probably didn't exist when it was sent. As absurd as this scenario is, a message is on its way.