My theory is this: interstellar travel requires some sort of warp drive, with or without dilithium crystals or beryllium spheres. But if you have warp drive don’t you also have time travel? Which is more likely, visitors from distant galaxies or anthropologists from some time in our distant future? I think they are coming back in time to figure out just what the heck we did to screw things up. 12 Monkeys, anyone? Gives a new meaning to Cole in your stocking.
“Gives a new meaning to Cole in your stocking.”
Good one!
Self replicating Von Neumann type probes from our interstellar neighborhood, having been launched a million years ago and having arrived millennia ago, carrying alien AI and DNA and plenty of robotics and cloning knowhow. The saucers aren't flying from other stars, they are flying from local underground/underwater bases.
This one is most convincing... mainly because there appears to be several time travelers in the picture. Most more careful than this young man.