Blast it or paint it: Asteroid to threaten Earth in 2013 RT Maybe SpaceX can get something whipped up to get up there quick... ...or we could just paint it
That's not a civilization-killer, but it would be pretty nasty if it were to hit land near a major city. Fortunately the world is 70% ocean, and hitting water wouldn't cause a huge tsunami or anything. The article mentioned it might break apart in the air. Actually large bodies like that don't simply break apart, they pretty much detonate due to massive thermal stresses. That's what happened during the infamous Tunguska event.
I had to google that, so for anyone that doesn't know: Tunguska event - Wikipedia, the free encyclopedia
Paint it??? What's that supposed to accomplish? Make it easier to see as it hurtles towards us? I'm reminded of a skit from the Royal Canadian Air Farce, back in their radio days, decades ago. The flight attendant on an airplane says, as part of the safety briefing (and in an annoyingly cheerful voice): "In the event that we plummet uncontrollably into the side of a mountain, an alarm bell will ring. It won't help, but it will notify you should you wish to scream."
What, are they trying to use the Poynting-Robertson effect? If you have enough advance warning even a very small deflection could make it miss the Earth.
Basically, yeah. Paint one side of it white, and light pressure will change the trajectory very slightly.