When you have the largest land mass on Earth, you’re an all-too-likely target.
This morning, Russia was hit once again by a space object, as a bolide exploded over Chelyabinsk, just east of the Ural Mountains, in western Siberia. Eastern Siberia is the site of the largest known strike in modern times, a little over a century ago. It hit in Tunguska in 1908, an air burst with the force of a nuclear weapon, leveling trees for miles around but fortunately injuring or killing few in the sparsely populated region. Had it instead hit in today’s (or even that day’s) New York City, the blast would have killed and injured millions.
And much larger events are possible. To the degree that such a thing can exist, there is now a scientific consensus that the dinosaurs (who didn’t have a space program) were wiped out by a large strike in the Yucatan sixty-five million years ago, clearing the way for placental mammals, who did eventually develop a space program.
Fortunately, today’s event was much smaller — an explosion high in the atmosphere as entry heating first melted and then boiled the ice inside the frozen rock from deep space, turning it to steam, which blasted the extraterrestrial intruder to pieces. But it happened in a populated area, and the shock wave shattered windows in buildings, injuring over a thousand people at last report. It’s interesting to note in observing the extraordinary video coming from Russia (partially a consequence of so many drivers having dashcams to protect against rampant police corruption) how accurate the special-effects folks in Hollywood have been.