In 100,000 years an alien ship enters our solar system. The earth has no remarkable intelligent life, but it's a beautiful biodiverse planet recovering from some bad extinctions. The aliens don't notice the traces left by humanity right away, this is just a survey trip and not much monumental remains.
But, they do pick up a signal, coming not from Earth, but from Mars. "How strange?" they think. Mars is obviously the inferior planet for life. Earth is incredible. But they go to investigate. 1/
