[butter pecan fan]

Astronomers and archaeologists suspect that our planet is struck by a 300 metre object like 2001 YB5 about every 5,000 years or so, but this is an estimate based on a hunch rather than on any definite evidence.

Assuming this is correct, and you're going to live another 100 years, the odds are one only in 50 that such a meteor will strike any point on the earth during your lifetime.

And any such strike would most likely hit water.

[blam]

"What does "if necessary" mean? The plane crashed into the Bank of America building. What threat would have necessitated a shoot-down if this action did not?"

The Tunguska explosion occurred in 1908, they are estimated to occur every 80-100 years.

[ChefKeith]

And any such strike would most likely hit water.

SURFS UP!