The asteroid, dubbed 2019 PK, was first spotted flying through space on August 5 this year. Since the initial observation was made, NASA has tracked the asteroid 39 times to determine its size, speed and trajectory. Based on the space agency’s calculations, the space rock will shoot past the Earth on the morning of Sunday, August 18. The asteroid flyby, NASA said, is classified as an “Earth Close Approach”.
Asteroid 2019 PK is an Apollo-type near-Earth object or NEO.
Apollo type asteroids fly around the inner circles of the solar system on trajectories similar to Asteroid 1862 Apollo.
If the space rocks – comets and asteroids – come close enough to the Earth and the Sun, they are dubbed NEOs.
NASA’s Centre for NEO Studies said: “As they orbit the Sun, Near-Earth Objects occasionally approach close to Earth.”
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Asteroid PK will visit Earth’s corner of space on Sunday morning, around 6.14am BST (5.14am UTC).
The space rock is estimated to measure somewhere in the range of 75.5ft to 167ft (23m to 51m) in diameter.
The asteroid is comparable in size to Nelson’s Column in Trafalgar Square, at the upper end of the estimate.
At the lower end of NASA’s size estimate, the space rock is still twice as long as a London double-decker bus.
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A similarly sized space rock struck Russia’s Chelyabinsk Oblast in 2013, when the asteroid unexpectedly entered the atmosphere.
The so-called Chelyabinsk Meteor exploded in the air before it hit the ground but the resulting arblast injured more than 1,000 people with shards of broken window glass.
Scientist Natalie Starkey warned of such an asteroid striking a big city like London.
Thankfully, NASA does not expect Asteroid PK to come close enough to pose any threat to the planet.
The US space agency said: “Note that a ‘close’ passage astronomically can be very far away in human terms: millions or even tens of millions of kilometres.”
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But the danger of unexpected asteroids hitting Earth is real, considering our limited knowledge of the number of threats lurking in deep space.
NASA said: “Given the current incompleteness of the NEO catalogue, an unpredicted impact – such as the Chelyabinsk event – could occur at any time.”
On Sunday, the space rock will come flying past our planet at speeds of around 7.37km per second or 16,486mph.
At its closest, the asteroid will approach the Earth from a distance of 0.02809 astronomical units or 2.6 million miles (4.2 million km).
The distance might seem like a lifetime away but on the larger scale of the cosmos, it is trivial.
A single astronomical unit – the distance between the Earth and the Sun – measures approximately 93 million miles (149.6 million km).