The fragment of the Mokoia meteorite in the Puke Ariki collection is a rare and precious find which contains some of the oldest known material in our solar system says a New Zealand meteorite expert.
Dr Joel Schiff, who founded Meteorite magazine, said Mokoia was classified as a CV3.2 carbonaceous chondrite, which were scientifically interesting and very rare. Only a tiny fraction of the total meteorites which have fallen worldwide have this classification.
Carbonaceous chondrite meteorites have fascinated scientists for many years because they have been found to contain many of the chemical building blocks of life such as hydrocarbons and amino acids. Dr Schiff said the Calcium Aluminium Inclusions (CAIs) in the meteorite, which look a little like white lichen growths, have been dated as 4.57 billion years, which made them the oldest known material in the solar system. Larger bodies like planets and meteorites started forming 10-50 million years later. "There is nothing on Earth as old as what you are holding in your hand" he said. "This one is really quite special".
Numerous researchers scattered round the world have pored over Mokoia, analysing it for all kinds of material and using it to propose various theories on the formation of life and the solar system. There was even a brief flurry of interest in the 1960s when some researchers believed they had found evidence of alien life. This sensational theory has since been discounted but further studies including Mokoia have continued.
While the meteorite has been "studied to death" new techniques may yet come to light which could reveal further useful data, Dr Schiff said.
The fragment held by Puke Ariki is larger than most that survive, tipping the scales at 76 grams and measuring approximately 44 x 34 x 35 millimetres. It has a distinct black fusion crust from its passage through the atmosphere and a slightly rounded shape which suggests it may have flown further from the main mass than some of the other recovered pieces. It appears someone has removed a small sample from it but the surface of the meteorite is sound and remains in remarkably good condition. Correspondence in the museum files suggests that the fragment was found by Cecil Hawken, presumably on his farm, and was given to the Olivers, a couple who worked for the Hawkens for many years. It appears to have arrived into the care of Taranaki Museum director Rigby Allan some time in the 1960s and its authenticity was confirmed by the Department of Scientific and Industrial Research in 1970.
FURTHER BACKGROUND ON THE MOKOIA METEORITE:
It was nicknamed the "deadly messenger" and it came from a clear blue sky. The residents of the Mokoia district had no warning when what sounded like rifle volleys, a blast furnace, or explosives sent stock stampeding and startled people out of their midday routines on 26 November 1908. Some witnesses reported seeing a "white flash" shooting across the sky leaving long white tails in its wake while others described a loud boom. A man rushed back from work, fearing that a powder magazine had exploded and others saw chunks of rock fall to earth before hitting a creek with a "splash and a hiss." More chunks thudded to ground about 180 metres from the homestead of Cecil Hawken where a group of children were playing. The explosion was heard for hundreds of kilometres and punters at New Plymouth's racecourse reported seeing the long tail of smoke lingering in the sky. The Mokoia meteorite had landed.
A first for New Zealand
It was the first meteorite seen to fall in New Zealand and it remained the only documented New Zealand fall where space rock was recovered until another one crashed through the roof of an Auckland home in June 2004. In all, at least nine meteorites have been recovered in New Zealand. It was later calculated that the Mokoia meteorite had passed directly over the district and exploded, scattering fragments before the main body splashed down off the Wanganui coast. The chunks of space rock that were recovered in the days following the fall were soon to become scientific hot property which stirred international interest and fuelled vigorous debate.
But at first it seems it took time for many people to realise just what had hit their busy rural settlement. While the bush telegraph started working and scattered reports began appearing in the newspapers, it was not until three days after the fall that William Syme visited the newly appointed Wanganui Museum curator George Marriner with a small dark coloured rock and news of the fall.
Marriner, an enthusiastic 29-year-old who had previously worked in the biology department at Canterbury College, sensed he was on to something extraordinary and he rushed to Mokoia on the first train the next morning.
After meeting with Hawken, who had heard parts of the meteorite crash down close to his home, Marriner found two lumps which had gouged a small hole at the base of a tree in a pine plantation. The two biggest pieces, both weighing about 2.3 kilograms, were surrounded by scattered smaller fragments along with a tree root which had been shattered by the impact.
Marriner's quick action had paid off and he had in his hands what he was to describe as "by far the most interesting meteoric find yet discovered in New Zealand." Both large chunks were deposited in Wanganui Museum.
News of the find caused an international stir and prompted breathless accounts of the fall as people shared what one Hawera and Normanby Times scribe termed "the sensational presence of the deadly messenger from the unknown." Another article a few days later posed a question which was to become the focus of scientists all round the world. "Whence comes this messenger through space? What fascinating experiences are enwrapped in those ounces or pounds of metal which come crashing to this globe, mayhap from other worlds?"
Marriner quickly started gathering evidence for his own scientific paper, advertising for eyewitness accounts and sending off fragments for analysis by various experts.
Just six months after it fell several bits of the meteorite had already been sent to Bristol, England, and were being examined by a prominent amateur astronomer,William Denning, who was suitably impressed.
"After observing many thousands of luminous meteors in the sky…it is interesting to hold a similar object in one's hand contemplating it from a much nearer standpoint," he said.
In hot demand
Since then, constant demands have been made on the chunks held in the museum at Wanganui and collection and samples are now scattered around the globe. The museum still holds some of Marriner's original find and fragments of the specimen are now also held in the University of New Mexico, the American Museum of Natural History, the Natural History Museum in London, Arizona State University and The Field Museum in Chicago, the Muséum national d'histoire naturelle in Paris and the Geological Survey of India in Calcutta among others. Many of these samples are only a few grams but they are carefully guarded nonetheless. A collector from the United Kingdom was trumpeting on the Internet about a recent exchange he made for a tiny crumbling piece of Mokoia last year, suggesting it still holds a lot of currency with collectors as well as scientists. But a century on from the fall the chance of any more fragments being discovered is remote.
Today the site of the fall is farmed by Mark Hawken, one of Cecil Hawken's great grandsons. It is still covered in pine trees although the original plantation is long gone. The story of the meteorite has been passed down the generations and the general area of the fall is well known, but the Hawkens don't have their own piece of space rock despite some sporadic searches of the area over the years.
The memory of the meteorite still lives on in the community and the farm still hosts the odd visit from the children of Mokoia School, who come to see where it all happened, he said.