[sickoflibs]

” Yep, a rock that NASA’s Asteroid Watch says was about 25 feet wide (approximately the size of a bus) and came within space-moments of smacking our planet around was completely unknown until April 28th. Four days ago. But no big deal guys, no need to panic. We’re fine. “

25 feet wide?

That's like a pebble. Call me when one the size of the US comes near.

[21twelve]

Had to search to see what sort of damage there might be and found the following (house sized, not bus).:

“Let’s say that an asteroid the size of a house crashed on Earth at 30,000 mph. It would have an amount of energy roughly equal to the bomb that fell on Hiroshima — perhaps 20 kilotons. An asteroid like this would flatten reinforced concrete buildings up to half a mile from ground zero, and flatten wooden structures perhaps a mile and a half from ground zero. It would, in other words, do extensive damage to any city.”

Later on they talk about a mile-diameter meteor would pretty much change life on earth.