Simulation of Asteroid 2012 DA14 close flyby of Earth. /
NASA/JPL Asteroids come and asteroids go, but every once in a
while one smacks into Earth. What happens on the day when we
know one is really coming? The question is not unwarranted,
given the fiery arrival Friday of a meteor that streaked across
the Russian sky, causing widespread damage and hundreds of
injuries from the air pressure wave, and as Asteroid 2012 DA14
recedes into Earth's rearview mirror after a close call on
Friday. It came within 17,100 miles of hitting our planet.
That's the closest recorded approach by a space rock that size,
one roughly 147 feet across. Now headed for an orbit closer in
to the sun, the space rock reached its closest point to Earth as
it passed directly above Sumatra on its 17,450 mile-per-hour
voyage. "Something that size would have hit the Earth with the
energy of a thermonuclear bomb," says asteroid impact expert Jay
Melosh of Purdue University in West Lafayette, Ind., who headed
a team that created an online impac