I'll make this quick.

I work for an astronomical society based in South America. At 1200hrs today a massive asteroid was spotted heading on a collision course with Earth. The media are expected to make an announcement in the next 5 hours starting with an address from the President of the United States. This is Genuine. Please take this as a friendly warning to prepare beforehand.

The Scientists over here have predicted that the Asteroid will make impact with Earth at approximately 2200hrs GMT on 2nd August 2012.

Respectfully.