Removing incoming asteroids will not just be an atomic bomb, a new study has revealed – and the difference is not just about power.
It is important to pick the right bomb to get the asteroid to go in the desired direction, and neutron power is the key. We now know that the Earth has removed a short-term threat from space and for the rest of the century the asteroid will be safe from Aphrodite, but eventually another spacecraft will threatened. Many methods have suggested dealing with this threat, but nuclear weapons are by far the most effective.
If an asteroid or comet is in the course of a collision with the Earth, the appropriate response will vary depending on a variety of factors; most importantly, the time is available. Those who have considered the problem have generally agreed that the best solution is to change the orbit of the asteroid carefully enough.
Air Force Institute of Technology Masters student Lansing Horan said in a statement, “Over time, many years before the impact, even a small speed change can increase the Earth-lost distance.” A dangerously large asteroid would still have to push hard enough to change this “miniscule” velocity. In popular hypothesis, a bomb shockwave can blow up an asteroid, but another important mechanism explained in Acta Astronautica: “An atomic device exploding over an asteroid radiates a certain surface area. Most of the material near the surface of this region melts almost instantly and / or evaporates by rapid energy accumulation from prompt X-rays, neutrons and gamma rays. Subsequently, this relatively small amount of superheated material expands away from the asteroid as a ‘blow-off’, the remaining majority of the asteroids inducing a pressure wave in the body.”
Neutrons do most of the work, but bombs emit neutrons with different energies, and the distribution varies with the type of atomic explosion. “If the energy storage input is wrong, we should not have too much confidence in asteroid deflation output,” Horan noted. Horan and co-authors begin by comparing the effects of a spherical silicon dioxide asteroid at 300 meters (one thousand feet) across neutrons at the top forces of specific fusion and split bombs, but there is still a long way to go.