The speedy asteroid is expected to swing by on a so-called “Earth close approach trajectory”. According to NASA, the asteroid’s closest approach will occur on the afternoon of Halloween, October 31. When this happens, NASA estimates the space rock will reach speeds of about 19,215mph (30,924kph).
What do we know about the Asteroid 2019 UJ3?
Astronomers have dubbed the rocky body Asteroid 2019 UJ3 after its discovery on October 19 this year.
The space rock is an Apollo-type asteroid, meaning it crosses Earth’s orbit on a path similar to Asteroid 1862 Apollo.
NASA has also classified the asteroid a Near-Earth Object or NEO.
NEOs are all comets and asteroids on orbital trajectories that come astronomically close to our planet.
In most cases, NEOs harmlessly zip past our planet without threatening impact.
But if an NEO is big enough to warrant interest from NASA, the space agency will keep a watchful eye on its estimated path.
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 asteroids approach brings it to within 1.3 astronomical units of the Sun, we call it a near-Earth object.”
Asteroid 2019 UJ3 is believed to measure somewhere in the range of 55.7ft to 124.6ft (17m to 38m) across.
Will Asteroid 2019 UJ3 hit Earth on Halloween?
Thankfully, NASA does not expect UJ3 to come close enough to pose any threat to Earth.
At its closest, the asteroid will approach Earth from a distance of about 0.01871 astronomical units.
One astronomical unit is the distance from Earth to the Sun – about 93 million miles (149.6 million km).
Asteroid UJ3 will shorten this down to just 1.7 million miles (2.79 million km) on the night of Halloween.
NASA said: “As they orbit the Sun, Near-Earth Objects can occasionally approach close to Earth.
“Note that a ‘close’ passage astronomically can be very far away in human terms: millions or even tens of millions of kilometres.”
Quick facts about asteroids and other space rocks:
1. Some of the bigger objects in the asteroid belt measure around 583 miles across.
2. NASA estimates a car-sized asteroid collides with Earth about once a year.
3. A football field-sized space rock slams into the planet roughly once every 2,000 years, according to NASA.
4. If a meteor survives the descent through the atmosphere it is called a meteorite.
5. Comets are different from asteroids because they are covered in icy layers that sublimate in space.