Earth Hit By 26 Nuclear-Level Asteroid Impacts Since 2000 - How Frequent Are ‘City-Killer’ Asteroids? [VIDEO]

A new report released by the B612 Foundation indicated that asteroid impacts, each with the power of a single nuclear explosion, may be more frequent than previously thought. While there have been zero nuclear explosions in recent years, the Nuclear Test Ban Treaty Organization’s (CTBTO) International Monitoring System (IMS) has detected 26 nuclear-level explosions caused by asteroid impacts since 2000.

Most, but not all, of these asteroid impacts occurred too high in Earth’s atmosphere to cause significant damage to the planet, but scientists are troubled by how these asteroids went undetected before they collided with the planet's atmosphere. According to the B612 Foundation, a private organization dedicated to creating an asteroid prevention and early warning system, an asteroid impact occurred in 2013 over Chelyabinsk, Russia, and although it reached the planet undetected, it caused damage to thousands of buildings in the city.

Former NASA scientist Ed Lu, CEO and cofounder of the B612 Foundation, wants to launch the Sentinel Space Telescope Mission, a deep-space early warning system that would detect Earth-bound asteroid threats using an infrared telescope.

“While most large asteroids with the potential to destroy an entire country or continent have been detected, less than 10,000 of the more than one million dangerous asteroids with the potential to destroy an entire major metropolitan area have been found by all existing space or terrestrially operated observatories,” Lu said in a statement.

The IMS currently consists of 269 facilities worldwide, and it can detect underground, underwater and atmospheric nuclear explosions. The explosions that were detected between 2000 and 2013 ranged from 1 to 600 kilotons. By comparison, the atomic bomb that was dropped on Hiroshima was equivalent to 15 kilotons of TNT. The Chelyabinsk impact was measured at 600 kilotons.

“Because we don’t know where or when the next major impact will occur, the only thing preventing a catastrophe from a 'city-killer'-sized asteroid has been blind luck," Lu said.

The B612 Foundation plans to launch the Sentinel Space Telescope Mission in 2018. The telescope will monitor more than 200,000 asteroids when it first launches. A video discussing the number of asteroid impacts since 2000 can be viewed below.