That puts it in the same general size class as the object that exploded over the Russian city of Chelyabinsk in February 2013, injuring more than 1,000 people.
Meanwhile, this asteroid which is nearly the size of a house will pass somewhere between 18,000-40,000 kilometers of the Earth's surface, just inside the space where geostationary satellites orbit in general. Its distance from the Sun is around 1.4 AU or astronomical units, with one AU equal to the average Earth-Sun distance or 93 million miles.
Early calculations conducted this summer by JPL led scientists to believe 2012 TC4 could come as close as 4,200 miles (6,800 km).
According to JPL, "The new calculations indicate that TC4 will fly safely past our planet on October 12, at a distance of about 43,500 km (27,000 miles) above the surface, or about one-eighth of the distance to the Moon".
"Slooh will train its telescopes on 2012 TC4 in an attempt to capture the fast-moving space rock as it passes between Earth and the moon", Slooh representatives said in a statement. Also, as the TC4 is expected to return to earth in 2050 and 2079, hence, we can get well prepared to counter its danger in future, if any.
In other words, if there's a real, Armageddon-style asteroid threatening Earth, expert bodies around the world will be able to detect it and hopefully be able to come up with a better plan than sending a bunch of oil drillers up in space to divert it away from sending us into oblivion.
Michael Kelley, a scientist working on the Nasa TC4 observation campaign, said: "Scientists have always appreciated knowing when an asteroid will make a close approach to and safely pass the Earth because they can make preparations to collect data to characterise and learn as much as possible about it".
As it stands, no asteroid now known is predicted to impact Earth for the next 100 years.