A giant asteroid, about the size of half a football field, will hurtle close by earth this week, coming nearer to the planet than communication and weather satellites.

Gardner-Webb University professor Don Olive described the 150-foot rock as "an oblong-type object tumbling through space" and said, most likely, humans will witness no affect from the asteroid.

Although it's not unusual for asteroids to fly past or even strike Earth, Olive said one this size comes close only once every four decades.

This particular rock has been tracked by scientists since February of 2012.

If the asteroid were to strike earth, Olive said it could be compared to about 2.4 million tons of TNT exploding.

"It would be a pretty significant event," he said. "It would blow down trees and kill everything in its strike zone."

The only similar comparison he could offer was when an asteroid fell to earth and exploded five miles from the surface in Siberia, Russia, in 1908.

"It's almost assured its going to happen again," Olive said.

The good news is, there are minimal chances of an asteroid of that magnitude striking a large city.

Olive said two thirds of the Earth is covered in water and only a small fraction of the land contains cities.

"We're actually a small target," he said.

Olive said smaller asteroids frequently enter the Earth's atmosphere but burn up and appear as shooting stars.

"Somewhere around 15,000 tons of meteors hit the earth every year, but most of it is the size of dust particles," he said.

The 130-metric-ton asteroid is expected to fly by Friday.

It can't be seen with the naked eye, and Olive said m ost astronomical telescopes aren't designed to track something moving that quickly.

He said it will only take about 40 seconds for the space rock to cross the full moon.

A nd it will only spend about an hour and a half passing through the " geosynchronous ring," the area where communications and weather satellites orbit around the earth.

"When things pass closer than that (geosynchronous) ring of satellites, then the fear is that an asteroid could hit some of our satellites and knock out communications systems or knock out important satellites," he said. "This asteroid is going to pass well within that ring."

Although it could potentially hit a satellite, Olive said the probability is small.

Despite the slight chances, he said various satellite companies are keeping an eye on the asteroid and NASA is regularly updating the rock's position.

"When this asteroid passes by earth it's going to be affected by earth's gravity so it's going to be flung out into space and we don't know what its orbit is going to be," Olive said. "Astronomers are watching for the next few months to see what it's going to do next. We don't really know what's going to happen after that."

Source: http://www.thetimesnews.com/news/the-odd-files/interactive-asteroid-comes-close-to-earth-1.95212