ASTEROID 2018 DU is blasting overhead today.

It’s about 10m across. It’s moving at about 4.6 kilometres every second. It will miss Earth by just 280,000km.

That puts it significantly closer to us than our Moon.

Asteroid 2018 DU is the 17th known asteroid to pass within one Lunar distance so far this year.

The pinprick of light was detected by a robotic telescope in Arizona, operated in conjunction with the Virtual Telescope Project in Rome.

In all there are some 17850 known near-Earth objects (NEOs). These are asteroids or comets that are known to have orbits that bring them within 194 million kilometres of the Sun.

Asteroid 2018 DQ passed even closer on February 21. About 8.8m across, it passed us at a speed of 21km/s at little more than 100,000km.

While there are millions of asteroids orbiting the Sun between Mars and Jupiter, rogue rocks and bundles of ice tend to only drift close to Earth only a few times each year.

The Chelyabinsk event was the explosion of a 17m large meteor over the southern Ural region in Russia. While it detonated in the atmosphere, the shockwave it produced damaged some 7200 buildings, with flying debris — mainly broken glass — injuring more than 1500 people.

NASA’s Planetary Defense Coordination Office is one of several organisations scouring Earth’s skies for such space rocks. Each discovery is tracked and analysed, with the results recorded at the Small-Body Database.

NASA has been tasked with locating 90 per cent of “potentially hazardous near-Earth asteroids”. These are defined as being at least 140 meters wide and passing about 7.48 million kilometres of Earth.