It appears that meteors of the sort that exploded in the air near Chelyabinsk in Russia are more common than scientists thought. The speeding rock caused a sensation when it streaked across the Russian sky last February, and the airborne blast created a concussion that broke windows. The bright light gave some people burned skin and the shock wave caused injuries on the ground.
Now some scientific analysis brings more information.
Most of the rock evaporated when it blew up 18.5 miles above Earth’s surface. Our atmosphere is 60 miles thick, or approximately the distance from St. Cloud to Minneapolis. So if the Chelyabinsk meteor were a metro area family returning home from a weekend up north at about 42,000 miles per hour (yes, that’s about how fast some of them drive), they made it to somewhere around Rogers before everything fell apart. That’s almost home by my reckoning.
Much of our worry has been focused on space rubble that’s more than a half-mile wide, but this lump was just 65 feet across. NASA is tracking more than 10,000 comets and asteroids though fewer than 1,500 have been classified as potentially hazardous to Earth. But the Chelyabinsk Chunk was made of a composite of gray and black stone, which reflects little light and is harder to spot. There may be more than 20 million asteroids with orbits that bring them close to Earth.
We can’t really protect ourselves against smaller space rocks. Gulp.
Where I once thought of space as cold, clean and empty, now I think of it as something like my basement, full of miscellaneous stuff I stopped thinking about.
Maybe rather than sending out movie-inspired space missions loaded with misfit deep-core drillers and explosives experts to destroy large threatening asteroids, we should launch misfit graffiti artists into orbit to paint the most threatening small debris so we can at least see it.
But this news, combined with our growing awareness of the long-term cost of concussions, will hasten the day when we all wear protective headgear most of the time, as both a fashion and safety statement.
Describe your everyday helmet – shape, color, decorations.