A 4.5 billion-year-old meteorite that blazed across southern skies before landing near Takapō will go on public display next week, offering visitors a rare glimpse of material older than Earth itself.
Otago Museum natural sciences curator Kane Fleury said the museum was “pretty excited” to unveil the specimen, describing it as a rare find in a country where only a handful of meteorites have ever been recovered.
The last of the 10 meteorites found was discovered in 2004.
The meteorite, weighing about 810g before samples were taken for analysis, is believed to date back to the formation of the solar system.
“It’s about as old as the origins of the planets within our solar system … older than the Earth, for sure,” Fleury said.
He said the rock’s journey began as part of the early solar system, before being flung towards Earth.
“At some point it has been thrown out of axis, and then being flung towards Earth, entered our atmosphere, burned up a wee bit and then landed.”
The meteorite’s fall was tracked using a citizen science camera network, Fireballs Aotearoa, after it was first spotted streaking across the sky on March 13, 2024, by Queenstown man Dennis Behan from his spa pool.
“As soon as he saw the meteorite enter the atmosphere as a big fireball, he quickly ran and checked the footage.”
Because multiple cameras captured the event, scientists were able to triangulate its path and narrow down a search area near Takapō.
Searchers located the meteorite remarkably quickly – within 30 minutes.
Dr Marshall Palmer, a geologist in the Department of Geology at the University of Otago, helped co-ordinate the recovery effort and has been analysing the meteorite to understand its origins better.
“Analysis shows the Takapō meteorite is an L5 ordinary chondrite and therefore was part of a parent asteroid between 100 and 1000 kilometres in diameter,” he said.
“This group of meteorites usually have Ar-Ar [argon-argon] ages of about 470 million years, which is attributed to the fragmentation event of the parent body; however, Ar-Ar dating of the Takapō meteorite is still progressing, as initial results were not clear. In any case, this fragment has spent hundreds of millions of years orbiting the sun before eventually intersecting with Earth’s orbit and falling in New Zealand.”
The meteorite’s appearance reflects its violent entry through Earth’s atmosphere, Fleury said.
“The rock itself has got ... [a] quite smooth, black, almost glassy texture to the outside of it … that’s what’s called a fusion crust. That formed when it entered the atmosphere, which heated the outside surface, which then melted it.”
Inside, the rock tells a different story.
“It’s got a cool cut surface which exposes the inner mineralogy … quite obvious large crystals of ... nickel and little bits of olivine,” he said.
He said some of the minerals found in meteorites are not formed naturally on Earth.
“That’s a pretty kind of crazy thought … there’s minerals floating around in the solar system that when they make it to Earth, that’s the only way that they’ve actually got here.”
To protect the meteorite, the museum has had to design an unusual display.
“It will be in a little box inside a case … completely airtight in an oxygen-free, moisture-free environment. That will slow the oxidisation and rusting process … so even the display of it is very, very special.”
Fleury said the museum felt privileged to house the meteorite, describing it as both scientifically important and inspiring.
“To be able to provide more knowledge and also inspiration is pretty incredible, and we’re pretty privileged to have this very, very special taonga on display for the public.”
He said the discovery also highlighted the importance of making finds of such national and international significance accessible.
Tūhura Otago Museum holds two of the 10 meteorites ever recovered in New Zealand.
The other is the Morven meteorite, discovered on a South Canterbury farm in 1925 and weighing around 7kg.
The Takapō meteorite will go on display in the Southern Land, Southern People gallery from Thursday April 23.
Ben Tomsett is a multimedia journalist based in Dunedin. He joined the Herald in 2023.