http://www.nasa.gov/topics/earth/features/2012.html
Straight from hourse mouth:
Q: Is NASA predicting a "total blackout" of Earth on Dec. 23 to Dec. 25?
A: Absolutely not. Neither NASA nor any other scientific organization is predicting such a blackout. The false reports on this issue claim that some sort of "alignment of the Universe" will cause a blackout. There is no such alignment (see next question). Some versions of this rumor cite an emergency preparedness message from NASA Administrator Charles Bolden. This is simply a message encouraging people to be prepared for emergencies, recorded as part of a wider government preparedness campaign. It never mentions a blackout.
Straight from hourse mouth:
Q: Is NASA predicting a "total blackout" of Earth on Dec. 23 to Dec. 25?
A: Absolutely not. Neither NASA nor any other scientific organization is predicting such a blackout. The false reports on this issue claim that some sort of "alignment of the Universe" will cause a blackout. There is no such alignment (see next question). Some versions of this rumor cite an emergency preparedness message from NASA Administrator Charles Bolden. This is simply a message encouraging people to be prepared for emergencies, recorded as part of a wider government preparedness campaign. It never mentions a blackout.