The asteroid, dubbed 2019 SG1, was first observed in the solar system on Friday, September 20. NASA has since tracked the asteroid 22 times to determine its size, speed and orbital path. The US space agency concluded Asteroid SG1 is flying in Earth’s direction on a “close approach” trajectory. The asteroid is expected to close-in on Earth tonight around 10.08pm BST (9.08pm UTC).
What do we know about the Asteroid 2019 SG1?
Asteroid 2019 SG1 is an Apollo-type rock orbiting the inner circles of the solar system.
Apollo-type asteroids cross the Earth’s orbit in a similar way to the Asteroid 1862 Apollo.
NASA has also classified SG1 as an NEO or Near-Earth Object.
NEOs are all comets and asteroids that come within 1.3 astronomical units (au) of Earth.
NASA said: “Some asteroids and comets follow orbital paths that take them much closer to the Sun and therefore Earth – than usual.
“If a comet or asteroid’s approach brings it to within 1.3 astronomical units of the Sun, we call it a near-Earth object.”
NASA estimates the space rock measures somewhere in the range of 24.3ft to 55.7ft (7.4 m to 17m) in diameter.
At the upper end of NASA’s guess, the asteroid is twice as long as London double-decker bus.
An asteroid this big would most likely disintegrate before it reached the ground.
Past impacts, however, prove an asteroid does not have to hit the ground to cause chaos and destruction.
When a 65.6ft-wide (20m) rock struck the atmosphere over Russia’s Chelyabinsk Oblast in 2013, the rocky object exploded before it struck.
But the resulting arblast spread over a wide radius, damaging more than 7,000 buildings and injured more than 1,000 people with shards of blown-out windows.
Will the Asteroid 2019 SG1 hit Earth tonight?
On its cosiest approach of our home planet, Asteroid SG1 will come within 0.00567 astronomical units.
A single astronomical unit describes the distance from Earth to the Sun – about 93 million miles (149.6 million km).
In other words, the asteroid will miss Earth by a safe margin of 527,059 miles (848,219.93km).
The distance is the equivalent of just 2.21 Lunar Distances (LD) or more than twice as far as the Moon is.