After reading an asteroid article that Neil Clement sent to me, I got to thinking about how Earth's population might react to the government announcing an inbound asteroid that is expected to impact our planet. It would likely make the Hawaii warning fiasco look pretty tame.
See this article 'Potentially hazardous asteroid' bigger than Earth's tallest building will zoom past us next month. We would have more warning time than what happened in Hawaii, and it would also give many people cause to think about their future existence. I can't imagine this being a period of calm reflection on the part of many. Churches might all of a sudden fill up on Sunday!
People don't panic unless they feel trapped. If you can't escape Earth, I suppose earthlings would start to reflect on their future existence.
What warning message would you broadcast using only 90 characters?