HOUSTON, March 19 -- A meteor exploded in the Earth's atmosphere in December creating the second largest fireball of its kind, the BBC reported citing NASA. The US space agency was informed of the blast by the US Air Force after it was picked up by military satellites. The explosion released 173 kilo tonnes of energy 25.6km above the Earth's atmosphere. A fireball this size is only expected two or three times every 100 years. "That was 40% the energy release of the Chelyabinsk meteor, but it was over the Bering Sea so it didn't have the same type of effect or show up in the news," Kelly Fast, the nearEarth objects observations programme manager at NASA, said. The explosion released energy 10 times equal to the atomic bomb in Hiroshima....