That was a close call!

Asteroid size of Gibraltar’s rock passes within 1m miles of Earth

IF you need a reason to be cheerful this morning, a good one may be that mankind avoided a catastrophic collision yesterday.

An asteroid roughly the size of the Rock of Gibraltar whizzed past the Earth in one of the closest shaves the planet has had in over a decade.

It hurtled past at about 73,000mph just over a million miles away – far enough to be safe but uncomfortably close in astronomical terms.

Officially called JO25 but nicknamed The Rock, the asteroid came closest to the Earth yesterday at 1.24pm.

It is a binary asteroid, which means it is made of two rocks that were originally separate bodies. While estimates vary, astronomers believe the asteroid could even be bigger than the Rock of Gibraltar which is 1,398ft high.

No other asteroid of comparable size has come this close to the Earth in the last 13 years.

The impact of the asteroid hitting the Earth would unleash as much energy as about 1,000 atomic bombs the size of the one dropped on Hiroshima in 1945. It would completely destroy a city the size of London or New York and cause extensive damage for hundreds of miles. Scientists first learned of The Rock three years ago when it was spotted by the Catalina Sky Survey, a US programme that uses two telescopes in Arizona to detect potentially dangerous nearEarth objects (NEOs).

While not big enough to cause an extinction level event, the effect of an object the size of The Rock hitting the Earth could be catastrophic on a regional scale.

Scientists at the University of Colorado have calculated it would take a 60mile-wide object to obliterate the human race.

Astronomers believe they know about 90 per cent of potentially hazardous asteroids bigger than 1,000m (3,281ft) across.

Smaller objects that are still large enough to cause a huge amount of destruction are a more worrying problem.

Only 30 per cent of 140m (459ft)sized NEOs have been detected and less than 1 per cent of those in the 30m (98ft) range.

Even a 30m-wide asteroid could cause significant damage. The asteroid that is thought to have killed off the dinosaurs 66million years ago was between six and eight miles across.

The Earth’s last close shave with an asteroid came in September 2004. The 3.1-mile wide asteroid Toutatis came within 963,000 miles – just over four lunar distances – of the Earth.

Robotic telescope service Slooh, which allows people to view space through a telescope online, is tracking the asteroid.

A Slooh spokesman said: ‘The Rock’s close approach ... is an alarming reminder of just how close these destructive chunks of space debris come to Earth.’