NASA Considers Nuclear Option to Deflect City-Killer Asteroid 2024 YR4

• NASA is evaluating the use of nuclear detonation technology to prevent a possible lunar collision by asteroid 2024 YR4 , a 60-metre-wide object expected to pass near the Moon in 2032 . While the asteroid poses no direct threat to Earth , scientists are studying intervention methods to avoid potential space debris hazards that could endanger satellites and crewed missions.

Renewed Planetary Defence Focus

• Discovered in December 2024 , asteroid 2024 YR4 follows an orbit that occasionally crosses the Earth–Moon system . Latest simulations indicate a 3.8% chance of striking the lunar surface. NASA, in collaboration with international teams, is considering mission timelines between 2029 and 2031 to design a deflection strategy.

Kinetic vs Nuclear Deflection

• Conventional kinetic impactors , such as those tested in NASA’s DART mission, may not provide enough force to alter YR4’s trajectory. Studies from NASA’s Jet Propulsion Laboratory suggest that only a nuclear standoff detonation could deliver sufficient impulse to redirect an object of this mass and velocity.

How the Nuclear Standoff Model Works

• Under this approach, a nuclear device would detonate above the asteroid’s surface , releasing radiation that vaporises part of the rock. The resulting gas expansion would create thrust, subtly changing the asteroid’s velocity without shattering it. This method offers rapid response capability when conventional deflection options are too limited by time.

Exam-Oriented Facts

• Asteroid: 2024 YR4 (≈60 ± 7 metres)

• Impact probability: 3.8% (Moon, not Earth)

• Proposed mission window: 2029–2031

• Technique: Nuclear standoff detonation (above-surface explosion)

• Possible effect: Temporary rise in lunar micrometeoroids up to 1,000×

Policy and Technical Hurdles
Any nuclear mission in space would require international approval under treaties restricting nuclear use beyond Earth’s atmosphere. NASA’s Planetary Defense Strategy classifies nuclear methods as last-resort measures , to be used only after confirming a genuine collision threat. The study of asteroid 2024 YR4 will serve as a critical test for both technology readiness and global coordination in future planetary defence efforts.