The mysterious boom and flash of light seen over parts of Virginia Sunday night was not a meteor, but actually exploding space junk from the second stage of a Russian Soyuz rocket falling back to Earth, according to an official with the U.S. Naval Observatory.
The Russian-built Soyuz rocket lifted off Thursday from the Central Asian spaceport of Baikonur Cosmodrome in Kazakhstan to launch a new crew and American billionaire Charles Simonyi — the world's first two-time space tourist — to the International Space Station. The spaceflyers arrived at the space station on Saturday.
link
To be fair, the Russians aren't attacking. In fact, the US military knew this was coming and expected it. Debris from launched spacecraft and rocketry regularly fall back into the atmosphere. Stilll, residents who didn't know that might well have thought that the Russians were invading when they dialed 911. Things might have gone rather differently a few decades ago.
I'd heard that they've got no idea what it was, but it was anything but a rocket.