Asteroid 2024 YR4 caused quite a stir last year when it was discovered and originally calculated to have a 3% chance of hitting Earth. However, in order to accurately deflect 2024 YR4, we need to know how much it weighs. But in either case, those missions would have to give up their intended targets in order to get close enough to 2024 YR4. It might not involve Bruce Willis sacrificing himself, but setting off a nuclear explosion at some height off the surface of 2024 YR4. Learn More:B. W. Barbee et al - Space Mission Options for Reconnaissance and Mitigation of Asteroid 2024 YR4UT - Will YR4 Hit the Moon?