An asteroid estimated to potentially exceed the size of London Bridge is expected to collide with the Earth's orbit on September 17. The remarkably massive space rock is being tracked by NASA as it whizzes at a speed of 19,371 miles per hour. Luckily, the Asteroid 2014 QJ33 will fly by the Earth's surface at a safe distance of about 1,592,819 miles away.

According to the BBC, NASA classified the celestial body as an Apollo asteroid and estimated its peak diameter to be around 110 metres wide. In comparison, London's river Thames spans roughly 104 metres. Being the closest fly-by of 2020, the asteroid falls into the category of a Near Earth Object (NEO) which according to the space agency can be any comet or asteroid that flies by the Earth within 1.3 astronomical units (AU). An AU is a unit of measurement that shows the distance between the Earth and the Sun.

These are celestial bodies that have been nudged by gravitational attraction of nearby planets into orbits. This in turn, allows them to enter the Earth's orbit. Scientists at CNEOS have predicted that Asteroid 2014 QJ33 will not be of any threat to human life.

Although in some instances these objects are less frequently referred to as "potentially hazardous asteroids" or PHA, NASA currently determines asteroids as PHAs if these have a minimum orbit intersection distance (MOID) of 0.05 AU or less than an absolute magnitude of 22.0 or less.

As of current time, NEOWISE data suggests there are about 4,700 potentially hazardous asteroids with a diameter greater than 100 metres in outer space. Biblical speculations on the end of the world have been linked to these PHAs although history has not seen any such asteroid that can cause such an apocalyptic event since the much talked about asteroid that wiped out the Earth 66 million years ago.

While such objects may seem undoubtedly massive enough to cause a seriously deadly impact on our planet, these NEOs that whizz by close to Earth's orbit post no immediate threat. To date, NASA has identified about 20,000 NEOs that come as close as 30 million miles of the Earth on a trajectory.

Most of the tracked asteroids don't really come in direct contact with the Earth's atmosphere, but in some rare instances, these giant space rocks can make an impact on the weather systems.

Asteroid whizzed past Earth
Whale-sized asteroid whizzed past Earth, noticed one day later Nasa