Most asteroid diversion schemes tend to involve some kind of impact – an explosion, a crash, a violent shove – but a French researcher has proposed an intriguing plan to alter the course of the asteroid Apophis before it swings into Earth’s neighborhood in 2036: offer the asteroid some shade.
A fleet of solar sail spacecraft could shift Aphophis’s course by simply shielding it from solar radiation, the researcher says.
The idea is to eliminate the so-called Yarkovsky effect, a phenomenon that produces a tiny amount of thrust on the warm side of an asteroid (named for Russian engineer I.O. Yarkovsky). As the sun heats one side of the rock it emits more thermal radiation on its near side, which affects the asteroids orbit ever so slightly.
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