Asteroids explode like nuclear weapons high in the sky more often than believed, based on a new study of the high-altitude events.
The Nuclear Test Ban Treaty Organization detected these blasts, as they kept watch for nuclear explosions on or above the Earth. They looked at explosions in the upper atmosphere between the years 2000 and 2013. The group discovered the Earth experienced at least 26 blasts as powerful as nuclear weapons during that time.
Some of these explosions were larger than the bomb that destroyed Hiroshima in 1945. These massive explosions took place far too high in the sky to cause any damage on the ground.
A map prepared by the B612 Foundation reveals a map of these nuclear-sized strikes. Explosions in the upper atmosphere were detected by low-frequency sound waves traveling through the solar system. These were recorded by equipment built during the cold war to monitor weapons tests.
Of the 26 strikes recorded during those 13 years, the smallest were around one kiloton - the same explosive force as a small tactical nuclear weapon. The most powerful had an explosive force equal to 600 kilotons. The most powerful hydrogen bomb ever exploded by the United States was the B83 bomb, at 1.2 megatons, roughly twice as powerful. The Tsar Bomba, designed and built by the Soviet Union, exploded on 30 October 1961 with a force of over 50 megatons.
In February 2013, an asteroid exploded over the city of Chelyabinsk, Russia, injuring 1,100 people in the city of 1.1 million people. The object was believed to be around 56 feet in diameter, and exploded somewhere between 16 and 19 miles above the metropolitan area.
Large asteroids have wiped out much of life on Earth in the past. The best known of these events took place 65 million years ago, wiping out most dinosaurs, leaving birds as their sole descendants.
Astronomers believe there may be around one million asteroids in our solar system large enough to destroy a city. Only 10,000 of those objects have been cataloged so far.
The B612 Foundation advocates building a space-based telescope to discover these remaining astronomical bodies. The Sentinel Mission aims to become the world's first privately-funded journey to deep space. Launched to a Venus-like orbit, it will begin the search for the largest asteroids.
"Sentinel is a space-based infrared (IR) survey mission to discover and catalog 90 percent of the asteroids larger than [460 feet] in Earth's region of the solar system. The mission should also discover a significant number of smaller asteroids down to a diameter of [100 feet]," researchers wrote on the program website.
The latest atmospheric explosions took place on 30 April 2013, above the north Atlantic.
The watchdog group prepared a video explaining their findings.