A MONSTER asteroid as big as New South Wales is cannoning past Earth so close it can be seen by the naked eye.

But don’t worry. It won’t bite.

NASA has calculated the space rock’s orbit carefully.

Despite being visible, it’s actually 170 million kilometres away. And the track it follows is never likely to cross that of our own planet.

But the ominous yellow-glowing orb can be seen passing through our skies both because of its size and the stuff it is made of.

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It’s more reflective than our moon.

It will be visible until it passes from sight on July 17. To find out where to look in the sky to find its unblinking eye, click here.

Named 4 Vesta, it’s the second most massive object lurking in the asteroid belt between Mars and Jupiter. It’s also somewhat odd.

It’s moving at 19.3km every second. It takes 3.6 years to complete each of its orbits.

The bundle of space rubble is some 525 miles (845km) wide, giving it a total surface area of about 800,000sq/km. The whole of New South Wales is 809,444sq/km.

To put that into perspective, the asteroid that exterminated the dinosaurs was just 15km wide.

What sets it apart from other asteroids is its density. It’s more closely compacted than most others. But it’s not massive enough to make it a true dwarf planet, such as Ceres.

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Vesta was visited by the Dawn space probe, which orbited it in 2011. The pockmarked body is believed to include areas of basalt, meaning it once had lava flowing over its surface.

An enormous crater has been blasted into its southern pole, cutting deep into its interior. There’s also a colossal ‘mountain’ towering some 20km above the rest of the asteroid’s surface — the second tallest in the known Solar System.