The equivalent of 1,800 tonnes of TNT: what we now know about the meteor that lit up the daytime sky over New Zealand
Meteorites hit New Zealand three or four times a year, but the fireballs that shot through the skies over the Cook Strait last week were unusual. It had an explosive power of 1,800 tons of TNT and was captured from space by US satellites. This triggered a sonic boom that was heard throughout the southern part of the North Island. Witnesses described a “giant bright orange fireball” and flashes that left “a trail of smoke that hung for several minutes”. The fireball was most likely caused by a small meteor, several meters in diameter, that crossed Earth’s atmosphere. That is one of only five impacts greater than a thousand tonnes of energy globally in the past year. Most meteors are small, creating “shooting stars” that only briefly penetrate the atmosphere. The meteor’s fragmentation generated a shockwave strong enough to be picked up by GeoNet, a network of earthquake seismometers, with flashes bright enough to be recorded by global lightning-tracking satellites. The Metservice’s