what I write...
I think this one merits at least a token post on the astronomy thread, but I'm taking no chances.
This video shows that one's chances of brushing off a meteor actually improve, using the Toyota deflection shield optional on their new trucks. Click for short video clip.
comparing the meteor impact to dynamite-type visuals in this commercial-
standard reference formula-
430,000 joules per 100 gm (8 inch) stick of dynamite.
This explosion looks like about 10, 8-in sticks, or
4.3 million joules for 1000 gms of dynamite.
and, KE = 0.5*m*v2
therefore, if the video showed what amounted to about ten small sticks of dynamite, and if the object is travelling about 400 mph (180.55 m/s), that would be a meteorite with either a mass of 264 kg; or, it could be a smaller mass, say 132 kg travelling at around 361 m/s.
if it weren't for the fact that the atmospheric drag will slow them down (except for the larger ones), I could imagine something the size of a tennis ball being this object, if it were not slowed from space...
the way I figured was 50 km/s in vacuo, slowed to 180 km/h by the atmoshpere, for the larger size meteorite (264 kg); or, 50 km/s, slowed to 361 km/h in the atmosphere.
The reason the smaller one goes faster is it was a larger one that broke up (!).