What if a huge asteroid is about to hit Earth? How to avoid natural catastrophe?

Conspiracy theorists have claimed in the past that the world would come to an end after an asteroid hits the Earth but this has fortunately not happened in recent times. However, one can't rule out the possibility of a meteoroid causing untold destruction as around 2,000 asteroids are reportedly being monitored by authorities.

It is also reported that an asteroid, nearly half a mile long, is also expected to pass closely by Earth in August 2027 though it is not clear if it will hit the planet.

Is it possible to avoid natural catastrophe if an asteroid is on its way to strike the earth? Richard Muller, Professor of Physics, UC Berkeley, and author "Now, The Physics of Time", says it is possible while responding to a query on Quora, a platform to share knowledge and better understand the world.

If there is a huge asteroid capable of destroying Earth that is going to hit us, how would we attempt to stop it (2017)? goes the question on Quora.

"The best method I've come across (in 37 years of thinking about this problem) is to explode a thermonuclear warhead a few miles above the surface. If done properly, the bomb would not break up the asteroid, but it would vaporize any volatiles on the surface (such as ice or methane). As these blew off they would provide a gentle and fairly uniform push to deflect the asteroid," wrote Richard Muller.

He went on to say that the bomb should be exploded before reaching the surface of the asteroid for maximum impact unlike the scene in Hollywood movie "Armageddon."

"The warhead could be one (or several) from our existing fleet of intercontinental ballistic missiles. We would just have to reprogramme their flight paths and their detonation programme. These weapons typically explode before they reach the surface, in order to inflict maximum damage in a war, so the modifications should not be difficult. The multiple warheads don't need to be detonated simultaneously, since the deflections can be quite small," he said.

Richard Muller also felt the need to test such a programme if an asteroid were predicted to hit the Earth, through international treaties, prohibits nuclear weapons in space at the moment. He said that an early deflection is important as a small change in orbit could help an asteroid to safely pass the surface of Earth.