The key to avoiding such a devastating scenario lies with asteroid detection, by finding all the asteroids that could hit Earth. Space agency B612 President Danica Remy told NBC: “It’s 100 percent certain that we’re going to get hit, but we’re not 100 percent certain when.” Planetary defence experts are now working on technologies to help prevent the earth from colliding with giant space rocks.
Ms Remy claimed: “The real issue is that we need to have an inventory of all the asteroids.”
The most well known example of an unexpected asteroid event was in 2013.
A 55-foot-wide asteroid hit the atmosphere over the Ural city of Chelyabinsk in Russia.
The asteroid mostly burnt up in the atmosphere before falling to the ground.
Astronomers have been scanning the skies for decades and so far there has been no sign of any giant planet destroyers.
NASA has estimated at least 95 percent of asteroids one kilometre (3,280 feet) or larger have been identified and pose no threat to Earth.
Brent Barbee, an expert on space hazards at NASA’s Goddard Space Flight Centre, is leading a study on what it would take to protect the Earth from an asteroid impact.
The team presented findings and outlined a concept for a Hypervelocity Asteroid Mitigation Mission for Emergency Response (HAMMER).
HAMMER would involve a fleet of spacecrafts that would bash into an oncoming asteroid or launch nuclear charges to send it off course.
Barbee described the studies as “the first steps towards designing spacecraft systems for asteroid deflection”.
The next steps in NASA’s planetary defence are already underway, at Johns Hopkins University’s Applied Physics Lab, where the team is developing a mission called the Double Asteroid Redirection Test (DART)
It is set to launch in 2020 and is the first embodiment of the HAMMER concept.
The DART craft will essentially act as a battering ram in space, flying into the asteroid at full speed and sending it off course for Earth.
In scientific terms it is known as a kinetic impactor.
Applied Physics Lab’s Andy Rivkin said: “We think we understand the physics of asteroid deflection in theory, but we’ve never performed an experiment at the right scale.”
The target is set to ram into a double asteroid named Didymos at 13,000 miles per hour.
DART will will be destroyed when it hits the smaller asteroid but scientists on Earth will be able to monitor any changes and movements in the space rock.
NASA believe in short-warning scenarios, missions like DART would not be enough, so HAMMER is also exploring the use of nuclear explosions.
The explosions would allow for more precision as they can be adjusted as to how close to the asteroid they explode.
Mr Rivkin said: “The asteroid threat is unique. It’s the only natural disaster that can be predicted and averted.”