13 Year Old Corrects NASA

[Viking]

Uh, one in 50? That's a 2% chance, right? How big is this asteroid, and should we be worried?

I'm unable to find a reliable source for this; NASA hasn't updated it yet anyhow. By the way, according to the article it is 1 in 450, and not 1 in 50. That's 0.0022 %.

It's size is 250 meters. If it's impact energy is indeed 400 megaton, then that is compared to the Tsar Bomba (50 MT) 8 times as powerful. The effects of the impact are 100% dependant upon whether it lands in the ocean or on land. If it lands on a continent the effects will only be regional I assume.

This might be the path of possible impacts; no idea about it's accuracy.