Should a near-Earth object (NEOs) ever threaten to hit the Earth, there may be a chance to alter its trajectory and avoid an impact. This is known as deflection.

This is harder than it sounds. There are many ways in which humanity could hypothetically deflect an asteroid. You can hit it with something to change its velocity. You could park a very large mass next to an asteroid and create a "gravity tug" to pull it off course. Or you could detonate a nuclear device. Each method has advantages and disadvantages—as of yet, there is no agreed-upon "best" deflection technique.

Unfortunately, due to the low probability of NEO impacts, national governments have provided very little research funding to study this problem in detail. The Planetary Society helps fill in this gap, funding projects to further our understanding of novel deflection techniques that, one day, may help save the world.

Beginning in 2010, The Planetary Society began a project to study the deflection technique known as laser ablation. Focusing a laser onto the surface of a NEO transforms some of its surface material directly from a solid to a gas. This gas forms into a plume of ejecta that is then expelled from the surface, acting against the asteroid, inducing a small, yet continuous thrust. Over time, this small thrust can significantly change the trajectory of an asteroid.

A swarm of small spacecraft each carrying a small laser (hence the name, Laser Bees) could be sent to a threatening NEO, zap its surface, and ultimately prevent it from impacting the Earth.



The process has several advantages over other deflection techniques: