2009-10-17
Explanation
This comic is a continuation of the Altarian alien invasion theme from a few days earlier (comic 1701). The main panel shows a crowd of people looking up at the night sky, where the moon has been graffitied with the message "HUMANS R GAY!!" The caption reads: "Never should have let the Altarians run ads on the moon."
The humor comes from imagining aliens who, having failed to destroy Earth with lasers, resort to the most juvenile form of insult possible -- essentially the equivalent of bathroom-stall graffiti, but on a cosmic scale. Writing "HUMANS R GAY" on the moon is the interstellar equivalent of a middle school bully's taunt, which makes the aliens seem more pathetic than threatening. It also satirizes advertising in public spaces by taking the concept to its most absurd extreme.
The votey panel extends the joke further: someone looks up and says, "Oh great. They also got Uranus?" with a small circle labeled "LOL" below it. This is a double punchline -- it implies the aliens wrote more juvenile messages on the planet Uranus, and the planet's name itself is the oldest astronomy joke in the book, which the aliens apparently also found hilarious.