Equivalent to 1,800 tonnes of TNT: what we now know about the meteor that lit up the daytime sky above New Zealand
In a piece on The Conversation senior lecturer in Astronomy Michele Bannister explains what makes the meteor that was seen in New Zealand last week so unusual.
It had the explosive power of 1,800 tonnes of TNT and was captured from space by US satellites. It set off a sonic boom heard throughout the southern parts of the North Island.
Witnesses described a “giant bright orange fireball” and a flash that left a “trail of smoke that hung around for a few minutes”.
The fireball was most likely caused by a small meteor, up to a few metres in diameter, traversing Earth’s atmosphere. It was one of only five impacts of greater than a thousand tonnes of energy globally in the past year. Most meteors are tiny, creating “shooting stars” that only briefly skim the atmosphere.
The fragmentation of the meteor produced a shock wave strong enough to be picked up by GeoNet, a network of earthquake seismometers, with a flash bright enough to be recorded by a global lightning-tracking satellite. The Metservice’s Wellington radar picked up the leftover smoke trail south of the tip of the North Island.