Part 5/14:
The most intuitive idea—detonating a nuclear device near or on an asteroid—runs into significant difficulties. A nuclear explosion beneath an asteroid's surface would typically produce a crater, but in the vacuum of space, most of the energy dissipates without rendering the asteroid harmless. If a nuclear missile is aimed directly at a fast-moving asteroid, it often destroys the missile before detonation or simply causes minor deflection rather than destruction.
Even drilling a nuclear device into an asteroid's core is impractical due to microgravity conditions and the high-speed approach. It would take too long and pose enormous landing risks, making it unfeasible for a last-minute mission.