If we see it coming in time, deflecting an asteroid requires a nuclear bomb mounted on a rocket of the kind we use for launching space probes; not petty cash, b

If we see it coming in time, deflecting an asteroid requires a nuclear bomb mounted on a rocket of the kind we use for launching space probes; not petty cash, but nowhere near hundreds of billions of dollars either. The "if we see it coming in time" part is the key.