Still, in the unlikely event that the starship made it all the way through interstellar space without hitting anything, without the crew members suffering mass sickness, hallucinations, or epidemic death, civil war, or descent into religious fanaticism or ordinary secular madness, what an embarrassment it would be for the voyagers to discover, upon reaching their coveted new home in space, Earth 2.0, that unfortunately it was already occupied by a race of intelligent aliens who were all too ready, willing, and able to protect their turf by blasting these intrusive space invaders to smithereens or, worse, vaporizing them into sheer nothingness.