Asteroid 2018 AJ was discovered by NASA on January 5.
Measuring 39 metres wide, the asteroid would undoubtedly cause death and destruction if it were to hit a city or closely-populated area.
An 18-metre asteroid that hit the city of Chelyabinsk in Russia in 2013 exploded with the force of 500,000 tonnes of TNT.
About 1,500 were injured after glass shattered on hundreds of buildings.
Will Asteroid 2018 AJ hit earth?
NASA admits it is not certain of 2018 AJ’s path at the moment.
It has given the asteroid a condition code of 7.
All new asteroids are given a condition code of between 0 and 9 based on how certain astronomers are about their course.
If a space rock scores zero, they are almost certain of its orbit but at the other end of the scale, 9 is classed as highly uncertain.
Scientists are predicting that 2018 AJ will bypass the Earth at a 4.7 lunar distance away, making it a potentially hazardous asteroid (PHA).
PHAs are space rocks larger than about 100m that can come closer to earth than 0.05au.
Au, or AU, stands for astronomical unit and is approximately the average distance between the Earth and the Sun, or about 150 billion metres.
One lunar distance is equivalent to 238,000 miles, meaning the asteroid will pass 1.1 million miles away – so a close whisker by NASA’s measurements.
There are currently 1,882 PHAs but NASA expects not to have a direct collision course with Earth.
Several asteroids were discovered last year by NASA but current estimates say we only know the location of around 3 percent of those out there.
A NASA spokesman said: “As of December 24, there are 17,495 known Near-Earth Objects (NEOs) around our planet; 17,389 are asteroids.
“Last year, we discovered 1,985 new near Earth asteroids. There were 1888 such objects discovered in 2016 and 1,571 in 2015.”