Kneel before Zod


Sixty-five million years ago, a Manhattan-size meteorite traveling through space at about 11 kilometers per second punched through the sky before hitting the ground near what is now Mexico’s Yucatán Peninsula. The energy released by the impact poured into the atmosphere, heating Earth’s surface. Then the dust lofted by this impact blocked out the sun, bringing years of wintry conditions everywhere, wiping out many terrestrial species, including the nonfeathered dinosaurs. Birds and mammals thus owe their ascendancy to the intersection of two orbits: that of Earth and that of a devastating visitor from deep space. (…)

In December 2004, scientists at NASA and the Jet Propulsion Laboratory (JPL), in Pasadena, Calif., estimated there was a nearly 3 percent chance that a 30-billion-kilogram rock called 99942 Apophis would slam into Earth in 2029, releasing the energy equivalent of 500 million tons of TNT. That’s enough to level small countries or raise tsunamis that could wash away coastal cities on several continents. More recent calculations have lowered the odds of a 2029 impact to about 1 in 250 000. This time around, Apophis will probably miss us—but only by 30 000 km, less than one-tenth of the distance to the moon. (…)

We considered several strategies. The most dramatic—and the favorite of Hollywood special-effects experts—is the nuclear option. Just load up the rocket with a bunch of thermonuclear bombs, aim carefully, and light the fuse when the spacecraft approaches the target. What could be simpler? The blast would blow off enough material to alter the trajectory of the body, nudging it into an orbit that wouldn’t intersect Earth.

But what if the target is brittle? The object might then fragment, and instead of one large body targeting Earth, there could be several rocks—now highly radioactive—headed our way.

{ IEEE Spectrum | Continue reading }

painting { Nicola Verlato }