An asteroid the size of a football pitch will zoom past Earth on Friday, coming close enough for Nasa to issue a warning.

The asteroid is scheduled to make its closest approach at 2.41pm GMT on Friday -

Asteroid 2008 OS7 is classified as “potentially hazardous” and is expected to come within 1.7 million miles of Earth – about seven times further out than the Moon – at a speed of around 11 miles per second.

Although that may seem like a long way off, it is close enough in space terms for Nasa to add it to its “asteroid watch”, and experts will be keeping a close eye on its approach.

The asteroid, which flies past Earth every 962 days, is scheduled to make its closest approach at 2.41pm GMT on Friday.

It is deemed potentially hazardous because it comes reasonably close to Earth, and could cause significant damage in the event of an impact.

It is estimated that a strike by an asteroid 1,500ft in diameter landing on a city would cause a crater 11 miles wide, instantly vaporising over 2 million people. The impact would be the equivalent of 141 gigatons of TNT, and the fireball released would kill a further 11 million people.

Dr Minjae Kim, a research fellow in the University of Warwick’s physics department, said: “We don’t need to worry about it too much as this asteroid will not enter Earth’s atmosphere, while it will still approach close to the Earth.

“There are millions of asteroids in our solar system, of which around 2,350 asteroids have been classified as potentially hazardous.

“One of the most intriguing aspects of the 2008 OS7 is its estimated diameter based on its luminosity and reflective properties, which ranges from 725ft to 1,622ft.

“This places it in the category of a small to moderately sized asteroid, roughly equivalent to the size of a football field.”

Asteroid risk and monitoring is carried out by the Center for Near Earth Object Studies at Nasa’s Jet Propulsion Laboratory.

Most asteroids and comets have orbits that do not bring them very close to Earth, and they are only classed as dangerous if they come within 4.6 million miles and are larger than 460 feet.

The next significant approach to Earth by a potentially hazardous asteroid will be by 99942 Apophis on April 14, 2029.

Nasa’s Osiris-Apex spacecraft is currently headed to the asteroid to study the physical changes that will result from its close encounter with Earth.

Apophis was also predicted to get dangerously close to Earth in 2068, but experts have since revised their calculations and no longer see it as a risk.

Nasa takes threat seriously

In total, five objects will pass close to the Earth between now and Friday, with the other four varying between 63ft and 120ft in diameter.

The asteroid coming closest is 2024BJ3, which is approximately the size of an aeroplane, and will come within 533,000 miles on Friday. All are too faint to be seen with the naked eye.

Nasa is taking the threat from space rocks seriously and in 2022 carried out the first asteroid deflection test, proving it could alter the orbit of the small moonlet Dimorphos.

 

It also sent a mission to the asteroid Bennu, which could hit Earth in 2182 with the force of 22 atom bombs.

Although the odds of a catastrophic strike are 1 in 2,700, Nasa was concerned enough to launch a spacecraft to Bennu seven years ago to collect samples, in case an Armageddon-style deflection mission is required.

The samples from the mission are now being studied by experts across the globe, including the Natural History Museum in London.