The amount needed to make a powerful nuclear device could fit in a small gym bag.

Instead, you would detonate a relatively small nuclear device next to the asteroid to nudge it a little off course.

Or a thermo nuclear device?

The blast took place only a few kilometers from where the first nuclear device had been detonated in 2006.

It involved detonating a 12-kiloton nuclear device in granitic rock at a depth of approximately below ground surface.