What should we do if a 'planet-killer' asteroid takes aim at Earth?

If a giant object looks like it's going to slam into Earth, humanity has a few options: Hammer it with a spacecraft hard enough to knock it off course, blast it with nuclear weapons, tug on it with a gravity tractor, or even slow it down using concentrated sunlight. 

from FOX News https://ift.tt/2HKvbLX
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