Alright people, let’s move on. Nothing to see here. You know that asteroid of death that whizzed by Earth today at an altitude that’s actually below some of our satellites? You know that meteor that exploded in the skies over Russia today, injuring nearly 1,000 people? And you know all that speculation that they’re somehow connected—that the Earth has stumbled into some kind of storm-front of space rocks, any one of which will annihilate us eventually? Forget it. The two incidents have absolutely nothing to do with each other, and neither one should cause us all that much worry. Yet.
It’s fair to say that if you live in the city of Chelyabinsk just to the east of Russia’s Ural mountains, you don’t want to be told that the blast that shook the region on an otherwise brilliantly clear day is nothing to worry about. At 9:20 AM local time, what is thought to have been a 10-ton rock moving 33,000 mph (54,000 k/h) exploded at an altitude of 18 to 32 miles (30 to 50 km), producing a several kiloton blast that damaged at least 270 buildings, sent hundreds of people streaming to hospitals for lacerations from flying glass and other debris and caused 20,000 emergency response workers to be mobilized. So that ain’t nothing. And after all the talk about the planet’s just-passed close shave with a much larger, 70-ton, 150 ft. (45 m) asteroid, it’s no wonder people are skittish.
But as Time reports in this week’s edition (available to subscribers here), this is nothing new. Earth has always lived in a cosmic shooting gallery, one that sends about 100 tons of debris plunging into our atmosphere every day. Most of it is no bigger than a pea and burns up long before it hits the ground, but we get at least one basketball-sized object every day too and at least one rock as big as a small car every few months. Much larger pieces come along less frequently—but inevitably.
With that kind of steady storm from deep space, it’s inevitable that a couple of big objects will arrive around the same time or even on the same day. Indeed, it probably happens a lot more than we realize, but we’ve begun paying only attention recently. It was in 1995 that Congress charged NASA with the job of keeping a constant watch on the skies and cataloguing all of the so-called near-Earth objects (NEOs) in our cosmic neighborhood, particularly the ones that could threaten the Earth. The big asteroid that flew by today, known simply as 2012 DA14, was discovered just last year and would have gone by totally unnoticed if we hadn’t been looking for it. The Russian meteor was much smaller and thus harder to detect, and may have approached from the direction of the sun, which can blind telescopes the same way it can partially blind you if you look straight up in the sky trying to follow, say, a plane.
But even if the Chelyabinsk blast was a routine thing—as far as exploding space rocks go, at least—that doesn’t mean that asteroid ordnance poses no danger. If 2012 DA14 had plunged through the atmosphere, it would have produced a 2.4 megaton blast, equivalent to 180 Hiroshima bombs. Russia already knew a thing or two about that kind of devastation: in 1908, a 330 ft. (100 m) asteroid exploded over the Tunguska region in the central part of the country, producing a 30 megaton blast—about 1,000 Hiroshimas—and leveling trees across 830 sq. mi. (2,150 sq. km).
(VIDEO: Meteorite Crashes Over Russia)
To defend against this kind of armageddon, NASA and other space agencies are working on ways to deflect incoming asteroids when they’re still years away from Earth—a relatively straightforward technology that involves rendezvousing with the objects and firing a heavy impactor into them, something NASA has done before to study comets and asteroids and sample their composition. But drawing-board technology is not the same as actual hardware, and it’s imperative that our good ideas are translated into in-the-hangar spacecraft.
The Chelyabinsk meteor and 2012 DA14 were never going to be doomsday objects, but they ought to be wake-up calls. Space is a crazy, crowded, messy place—and like it or not, we live there.