If everyone on the planet was to die now and 500 years were to pass by. What do you think will be some of the first things that will be immediately discovered by a visiting alien scout ship? What impression will they have about mankind?
The remains of the buildings and cities that we built. The damage that we've done to the environment will be largely repaired by then I think. They will see a culture of builders, but they will also note that we seemed to be at war with nature itself. Then they will see the remnants of vast, interconnected transportation systems, again noting that we were builders but we bent nature to our will rather than conforming to nature. Lastly, they see vast areas of land dedicated to our dead. This will probably lead to acknowledge that we venerated our ancestors and also that we had some type of deity or deities that we worshiped.