NEW ZEALAND: On July 7, 2022, a bright-green meteor was smashing into Cook Strait, between New Zealand’s North Island and South Island. The meteor, approximately 3.3 feet (1 metre) in diameter, struck with an explosive force comparable to 2,000 tonnes (1,800 metric tonnes) of TNT, creating a tremendous sonic boom. Two weeks later, a second unusual green fireball was captured on camera over Canterbury on New Zealand’s South Island.
Fireballs are meteors that are larger than one metre in diameter and unusually bright. Why are there so many fireballs lighting up the skies above this island nation when only four or five are typically reported over any one region each year? So, what gives these meteors their distinct green colour? The size, height, and chemical composition of the meteors will determine whether the wakes, which may last only a few seconds, are green or not.
According to Jack Baggaley, emeritus professor of physics and astronomy at New Zealand’s University of Canterbury, “the source of green in a long-lasting meteor wake after the meteor is restricted to those above roughly 62 miles (100 km).”
Solar particles ionize oxygen in the upper atmosphere while considerably smaller meteors with speeds of up to 45 miles (70 km) per second reach the Earth’s atmosphere. The same theory produces green auroras.
People are also speculating that these fireballs had something to do with the Perseid meteor shower, which takes place every year from mid-July to late August.
According to Lunsford, the Perseids’ rapid velocity can make ionized oxygen atoms glow with a greenish tinge when meteors move through the atmosphere, but he doesn’t believe the New Zealand fireballs are related to the Perseids.
That timeframe doesn’t fit well with the early-July sightings because this year’s Perseids last from July 17 until August 24 and peak from August 12 to August 13. The Perseid meteor shower’s radiant point, Perseus, can only be viewed in the Northern Hemisphere’s night sky.
Unfortunately, the Perseids peak this year will probably be less spectacular than in years past. The super moon in August, which will bleach the night sky and make most meteors challenging to spot, occurs at the same time as the peak of the meteor shower.