But is it worth all the effort? Although an asteroid strike would be catastrophic, some argue that planning for unlikely disasters ignores the real problems facing the planet.
Giant magnet ‘to break up asteroids’
Rock on: As scientists propose a magnetic shield to pull "rubble pile" asteroids away from Earth, experts debate whether we should be targeting space rocks or focusing on the more immediate climate crisis. Glossary
Asteroid - A small body in space, made of metal and rock material. Asteroids usually orbit the sun, but if knocked off course they can be drawn into Earth’s gravity and fall towards it.
Trajectory - The path or progression that something follows forward.