(Space.com)—The dramatic fireball that exploded over Russia today (Feb. 15) was apparently the biggest such blast in more than a century, scientists say.
The object that caused the Russian fireball, which damaged hundreds of buildings and wounded perhaps 1,000 people in the Chelyabinsk region, was originally probably about 50 feet (15 meters) in diameter and weighed roughly 7,000 tons, said Peter Brown, director of the Center for Planetary Science and Exploration at the University of Western Ontario in Canada.
From multiple sensors using multiple technologies, a best initial estimate of the total energy of the event is about 300 kilotons of TNT-equivalent, Brown said, though he stressed that the number could change as scientists learn more.
“This could easily be in error by a factor of two,” he told SPACE.com. “I am confident, however, that it is in excess of 100 kilotons, making it the largest recorded event since the 1908 Tunguska explosion.” [Photos of Russia's Meteor Fireball Blast]
In that 1908 event, a 130-foot-wide (40 m) object exploded over the Podkamennaya Tunguska River in Siberia, flattening about 825 square miles (2,137 square km) of forest.
In a cosmic coincidence, the most recent Russian fireball exploded just hours before the 150-foot-wide (45 m) asteroid 2012 DA14 was set to cruise within 17,200 miles (27,000 km) of Earth today, marking the closest approach of such a large space rock that scientists had predicted ahead of time. The two events today are unrelated, NASA researchers say.