Scientists at Sandia National Laboratories have made significant strides in nuclear power-assisted planetary defense. Their research demonstrates how a nuclear blast could potentially save Earth from a catastrophic asteroid impact. By vaporizing a part of the asteroid’s surface, they show that we can nudge the space rock off its collision course.
Asteroid impacts, although rare, have proven to be devastating. The event that wiped out the dinosaurs 66 million years ago involved an asteroid about six miles wide. However, smaller asteroids can still cause significant damage. In 2013, a 60-foot-wide meteor exploded over Chelyabinsk, Russia, injuring over 1,200 people. To avoid such dangers, scientists are exploring various methods to shield the planet.
In 2022, NASA’s Dart probe deliberately crashed into Dimorphos, a small moonlet orbiting the asteroid Didymos. This kinetic impact demonstrated that nudging an asteroid could protect Earth, but it requires years of warning to be effective. The nuclear option offers an alternative for larger asteroids, especially when time is short.
Contrary to Hollywood portrayals, such as the movie Armageddon, this approach does not involve drilling into the asteroid. Instead, scientists propose a “standoff explosion.” The blast vaporizes part of the asteroid’s surface, creating an expanding gas that pushes the asteroid in the opposite direction. Dr. Nathan Moore, the lead author of the study, describes it as turning the asteroid into its own rocket.
Moore and his team tested this theory by exposing mock asteroid pieces to intense X-ray pulses similar to those generated by a nuclear explosion. The experiment, which lasted only 20 microseconds, showed how a nuclear blast could propel the asteroid material at speeds of nearly 200 mph. This strategy could work for asteroids up to 2.5 miles wide, and possibly even larger, depending on the warning time available.
While the nuclear option is effective, some scientists prefer non-nuclear methods like kinetic impactors. Colin Snodgrass from Edinburgh University emphasizes the importance of scaling these experimental results to full-size asteroids. The European Space Agency’s Hera mission, launching next month, aims to assess the aftermath of NASA’s Dart mission.
Gareth Collins, a planetary scientist at Imperial College, acknowledges the promise of nuclear-based asteroid deflection. However, he still favors kinetic impactors for their technological feasibility. That said, in situations where time is limited or the asteroid is especially large, the nuclear approach might be Earth’s only option.
This groundbreaking research could pave the way for more advanced planetary defense strategies, offering hope in the face of future asteroid threats.