The hefty meteor that exploded above the Russian city of Chelyabinsk on February 14, 2013 (9:23 a.m. local time) sent a shock wave that damaged buildings, shattered windows and rained debris across the city injuring hundreds of people. Had it arrived at Earth at a different time of day it could have hit Moscow, Belfast, Dublin or any number of other cities with a latitude similar to that of Chelyabinsk.
"The Chelyabinsk meteorite was frightening and several hundred people were injured, but the damage was minor compared to what could occur with an object only slightly larger," said John Tonry, ATLAS Prinicipal Investigator. "Such an object could kill thousands of people and devastate a city. Our goal in building the ATLAS system is to find these objects and provide warning for emergency action."
The Chelyabinsk meteor entered the Earth's atmosphere at around 40,000 mph before breaking into chunks and streaking the sky with fireball and vapor trails. It was estimated to be about 50 feet across with a mass of 10,000 tons. Its explosion in the atmosphere was equivalent to about 500,000 tons of TNT.
Most injuries in Chelyabinsk – a city of about one million people – resulted from flying glass. At least three craters were discovered with one almost 20 feet wide. Another lump of the meteorite is thought to have crashed through thick ice on a nearby lake.
NASA officials said the Russia meteorite was not related to asteroid 2012 DA14, which flew by Earth safely on Friday. If that asteroid had hit Chelyabinsk instead, the entire city would have been completely destroyed. "City killer" impacts Earth occur about every few hundred years. The most recent such impact occurred about 103 years ago – the Tunguska impact – in Siberia. ATLAS is designed to provide advance warning for the impact of objects like the Tunguska impactor.