American physicists from Sandia National Laboratories have described an unobvious way of using nuclear warheads to protect the Earth from dangerous asteroids. The study was published in the scientific journal Nature Physics (NatPhys).
The most obvious method of using nuclear weapons against an asteroid would be to directly strike the threatening object, the team says. However, this could result in the space rock breaking into many fragments that would rain down on the planet.
Instead of direct bombardment, the researchers proposed detonating a nuclear warhead about two kilometers from the asteroid, bombarding it with powerful X-ray radiation.
The X-ray pulse is capable of vaporizing part of the asteroid, changing its trajectory and deflecting the object from Earth.
In the new study, scientists used one of the most powerful laboratory radiation sources in the world, called the Z Machine. The setup is used to generate electrical pulses and X-rays to study the properties of materials under extreme pressure and temperature.
Physicists have simulated the X-ray pulse from a nuclear explosion by generating a plasma cloud by compressing argon gas using magnetic fields.
Scientists placed a pair of quartz targets, each 12 millimetres wide, in a vacuum.
The X-ray pulses generated jets of steam from each target and accelerated them to speeds of about 250 km/h, in line with computational predictions.
Scaling the results to a four-kilometer-diameter asteroid and a megaton nuclear bomb detonated two kilometers from its surface, the researchers suggested that the resulting jolt could deflect dangerous asteroids away from Earth.
