Apocalyptic asteroids have chink in armour

摘要

WHEN you need to save Earth from an incoming asteroid, try shooting at its bright spots. A new analysis of fragments of the Chelyabinsk meteor, which exploded over Russia in 2013, suggests that firing something at an asteroid's lighter areas may be the best way to deflect it. The Chelyabinsk object arrived without warning, injuring around 1500 people. If would-be planetary protectors do spot something similar en route, they could use a projectile to shift it off course. But figuring out how is tricky, and not something to be trying for the first time with an asteroid hurtling toward us.