The massive space rock, which causes the dramatic Geminids meteor shower, is speeding through space at 45,000mph towards our planet.
NASA has branded the object, named 3200 Phaethon, “potentially hazardous”.
However, the likelihood is that it will just skim past the Earth before heading off to orbit the sun again.
At 5km wide, the asteroid is one of the largest ever discovered in our solar system.
However, it is still only around half the size of Chicxulub, which helped wipe out the dinosaurs 66 million years ago.
And it will be closest to the Earth at 10pm this evening, narrowly missing us.
Although there is potential for danger, experts say it will miss Earth’s orbit by 2 million miles – a hair’s breadth in astronomical terms.
NASA said on its website: “This ‘potential’ to make close Earth approaches does not mean a potentially hazardous asteroid will impact the Earth.
“It only means there is a possibility for such a threat.”
Should conditions be clear, stargazers may even be able to catch a glimpse of its journey past us using a telescope.
Scientists are hoping the unusually close proximity will allow them to capture images of the object and put together a reliable 3D model.
The space rock has been named after the son of the Greek sun god Helios who pulled the sun across the sky.
It is also responsible for causing this week’s stunning Geminids shower, which returns ever December – although scientists are not sure how.
The Geminids were first observed in 1862, much more recently than other meteors such as the Perseids and Leonids that date back to antiquity.
Because they enter Earth’s atmosphere at an angle, the Geminids also have a slower closing speed than many other comets.
As they hit the air and burn up they are travelling at about 79,200mph.
In comparison, the Perseids approach Earth at 133,200mph and the Leonids at 162,000mph.