Apophis, a 240-mile wide remnant of the early solar system believed to be made mainly of rock, circles the Sun in an orbit that brings it close to the Earth every few years.
It will pass within 22,400 miles of our planet in 2029 - closer than the satellites used in our communication systems. Scientists currently estimate the likelihood of Apophis hitting our planet at one in 45,000.
However, if in 2029 it passes through a small region known as the "gravitational keyhole", which is influenced by Earth's gravity, the chances of it being diverted on to a collision course and hitting us on April 13, 2036, will shorten considerably, they say.
Scientists say in the event the asteroid collides with the Earth it would unleash a force 100,000 times stronger than that generated by 'Little Boy', the Uranium bomb dropped by the US on Hiroshima on August 6, 1945.
The impact would create a massive crater, potentially leave the whole planet in the dark for a year or more because of the dust released into the atmosphere, destroy crops, and unleash tsunamis that would destroy coastal settlements.
Now, scientists at Stevenage-based space company, Astrium plan to send a satellite to orbit around Apophis in 2014, when it is 41 million miles from Earth, to gather the crucial data needed to help divert its path.
Astrium space science director, Dr Healy said, the 250,000 pounds 'Apex' mission will collect data on the composition of the rock that makes up Apophis, its precise orbit, spin axis and spin rate.
"It is imperative to collect data on Apophis as soon as we can because once we know it's on a collision course the safest way to avoid disaster is to nudge the asteroid to change its orbit. We think that by 2036 there is a significant risk of collision. Up until around 2025, it would be relatively painless to do something about it," said Dr Healy.
"You could ram it hard with a one-tonne spacecraft and it would change momentum enough to shift it. If you leave it any later you either have to use much more mass or use a nuclear bomb to achieve greater impact," the Daily Telegraph quoted him as saying.