Earth at risk for strike by large meteor within 60 years, NASA head says

Every 60 years, a meteor could hit Earth and cause serious damage, which is why the possible threat should be taken more seriously, the head of NASA said Tuesday.

NASA administrator, Jim Bridenstine, spoke during the International Academy of Astronautics Planetary Defense Conference in College Park, Maryland. He said detecting, tracking and studying meteor and other near-Earth objects is a big project NASA is working on.

"We have to make sure that people understand that this is not about Hollywood. It's not about movies. This is about ultimately protecting the only planet we know right now to host life, and that is planet Earth," he said.

To illustrate his point, Bridenstine recounted a meteor strike incident that only happened six years ago.

On Feb. 15, 2013, a small city in Russia called Chelyabinsk experienced severe damage from the shockwave of a 65-foot meteor that broke apart in the atmosphere. The energy equivalent to the blast was around 44,000 tons of TNT, according to NASA.

The explosion happened about 14 miles above the city, damaging 7,200 buildings in Chelyabinsk and five other towns. It also caused more than 1,500 people to seek medical treatment, mostly for cuts from broken glass.

That very same day, hours after the heavy damage to Chelyabinsk, Bridenstein said a 75-foot meteor was detected about 17,200 miles away from Earth. It passed the planet, but the impact of it could have been worse, he noted.

"I wish I could tell you that these events are exceptionally unique - but they are not," Bridenstine said.

He added that similar incidents can occur about once every 60 years. Within the last century, three other impacts have happened, including a large meteor wiping out hundreds of square miles of forest in a remote part of Russia in 1908. Another meteor impact was reported in Brazil in 1930.

Bridenstine said that NASA is working to detect, track and characterize near-Earth objects that are 140 meters (about 460 feet) or bigger. The impact of those meteors could destroy a state or even a small country.

He noted that there are about 25,000 such objects in space right now, but so far only about one-third of them have been detected. NASA is working toward a goal of detecting 90 percent of those objects, but Bridenstine did not provide further details on when or how that could be reached.

The conference, which will last until Friday, will host forums and focus on a realistic exercise to study and detect objects that could hit the planet.