NASA is on alert as an asteroid the size of a football field is set to zoom past Earth this week

NASA has its eyes on a “potentially dangerous” near-Earth asteroid with a diameter of 250 meters – about the size of a football stadium.

Asteroid 2008 OS7 will make its closest pass to Earth on Friday, February 2.

However, the closest approach will be no closer than 1,770,000 miles from Earth.

The NASA Jet Propulsion Laboratory Asteroid Watch website has outlined the giant space rock as something to watch.

Will I be able to see asteroid 2008 OS7?

Amateur astronomers will have to retreat, however, because 2008 OS7 will not be visible to the naked eye or with the average telescope.

According to Dr. Kim, “Unfortunately, asteroids are generally too faint to be detected with current techniques and surveys, so it is very difficult to see them with the naked eye.”

“The only asteroids visible to the naked eye so far are Pallas and Vesta, with a diameter of about 500 km.”

There are numerous “potentially hazardous asteroids” or PHAs in our solar system.

Dr. Kim explains, 'There are over millions of asteroids in our solar system, of which [roughly] There are 2,350 asteroids classified as PHAs.

“The next major approach to Earth by a PHA will be 99942 Apophis on April 14, 2029.”

As space rocks go, asteroid 2008 OS7 is quite small.

According to Dr. Minjae Kim, Research Fellow in the Department of Physics at Warwick University, called OS7 “a very small asteroid” in 2008.

But because its orbit crosses that of Earth, the asteroid is classified as a “potentially hazardous asteroid (PHA).”

Dr. Kim added: “One of the most intriguing aspects of the 2008 OS7 is its estimated diameter based on its brightness and reflective properties, ranging from 0.221 to 0.494 kilometers.

'This puts it in the category of a small to medium asteroid, about the size of a football field.

“We don't have to worry too much about it as this asteroid will not enter Earth's atmosphere, while it will still approach close to Earth.”

The next time asteroid 2008 OS7 will pass Earth will be in 962 days, when it completes its orbit around the sun.