this was a good topic, I have one off topic post
Proposed Missions Could Deflect Space Rocks Like Asteroid Apophis:
While scientists keep a close watch on the myriad space rocks near Earth, they don’t yet have a solid plan on what to do if one appears headed on a collision course toward our planet.
Two new studies propose potential spacecraft missions that would collide with asteroids in an attempt to deflect them away from our planet. Such missions, some researchers say, may be among our best hopes to ward off asteroids that may pose a threat to Earth.
One concept from researchers in China involves deflecting an asteroid with a spacecraft propelled by solar sails, giant mirrors that fly through space via the force of sunlight reflecting off them. A possible target is the asteroid known as Apophis, named after the Egyptian god of darkness because of fears that it might crash into Earth.
the possibility of impacting down has increased
from 1 to 250.000
from 1 to 233.000
but it's still low possibility to impact
The asteroid Apophis is expected to fly harmlessly by Earth on April 13, 2036, with only a 1-in-233,000 chance of hitting our planet, while neither of the two asteroids studied for the Don Quijote mission, designated 2002AT4 and 1989ML, is close to crossing Earth's orbit.http://www.space.com/12781-space-missions-deflect-dangerous-asteroids-apophis.html