Just some numbers for those who think about diverting the asteroid by pumping energy into it.
Assumptions:
- $60$ km diameter, same as https://en.wikipedia.org/wiki/Chicxulub_impactor
- $113097 km^3$ volume
- $2g/cm^3$ density, https://en.wikipedia.org/wiki/Standard_asteroid_physical_characteristics#Density
- $2.262*10^{17}kg$, http://www.wolframalpha.com/input/?i=113097+km%5E3*2g%2Fcm%5E3
- If we impart an impulse in 3 months(ie. 9 months before impact) we need a delta-v of $0.27m/s$.
- This will take $2.944*10^{8}TJ$. http://www.wolframalpha.com/input/?i=2.262*10%5E17kg%28%2827m%2Fs%29%5E2%29+in+TJ
- Or about 75 times the total energy yield of all nuclear bombs detonated to date.
- This does not include the energy needed to get a bomb to the asteroid.
Sorry about the links being mangled. Copy-paste should work, if you can fix I will accept edits.