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Astronomie - Seltener Meteorit blieb seit 140 Jahren unbemerkt

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A rare meteorite that formed soon after the origin of the solar system has been discovered in a private geological collection – 140 years after it fell to Earth. The stone, which is around 4.6 billion years old, was officially handed over to Naturalis Biodiversity Center in Leiden, the Netherlands, earlier this week.

Bright lights and sizzling sounds accompanied the fall of the meteorite on 27 October 1873 in the village of Diepenveen in the Netherlands, according to a contemporary handwritten note. Two witnesses to the fall dug up the small, warm stone and gave it to the local schoolmaster. It remained a school specimen until 2009, when it was given to a collector. Dutch amateur astronomer Henk Nieuwenhuis then "rediscovered" the 5-centimetre-wide space rock when he examined the collection last year.

"It is very unusual for a space rock to remain unnoticed by astronomers and geologists for such a long time," says Leo Kriegsman, a geologist at the Naturalis Biodiversity Center.

The Diepenveen, as the meteorite is now officially called, is only the fifth to have fallen in the Netherlands as far as we know. The find is all the more remarkable because the meteorite turns out to be of a very rare, carbon-rich type known as a CM carbonaceous chondrite – the same type as the one that triggered a meteorite hunt when it fell to Earth in California last year.

"CMs comprise less than 1 per cent of all known meteorites," says geologist Marco Langbroek of the Free University in Amsterdam, where the Diepenveen underwent its first analysis.

CM carbonaceous chondrites contain up to 2 per cent carbon, often in the form of microscopic diamonds. They also contain organic matter like amino acids, which some researchers believe brought the building blocks of life to Earth.

"It is very interesting news," says meteorite researcher Peter Brown of the University of Western Ontario in London, Canada. "CM meteorite falls are indeed rare. If the meteorite has been stored well and not subjected to too much terrestrial contamination it could be quite interesting."

However, fellow meteorite researcher Michael Zolensky of NASA's Johnson Space Center in Houston, Texas, is more cautious. "It will be thoroughly contaminated in any case, so only results for non-terrestrially occurring amino acids may be believable," he says.

Tiny samples of the brittle and porous meteorite are now being studied at laboratories in California, New Mexico and Switzerland. "We hope to publish our analysis results sometime next year," says Langbroek.

Quelle: NewScientist

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New Dutch meteorite fell in 1873

 

The stone has a rare composition of scientific importance.

140 years after its fall to earth, there is official recognition at last: the rock that landed near the Dutch village of Diepenveen back in 1873 is the fifth Dutch meteorite. The “Diepenveen”, as it’s called, has an unusual composition and may contain complex molecules that could perhaps have played a role in the origin of life on earth.

"A blinding light"

Around 3 o’clock in the afternoon of the 27th October 1873, a piece of rock plummeted to earth narrowly missing people working in the fields of Diepenveen, a village lying to the east of the Netherlands near the town of Deventer. “There was a blinding light and much hissing as this rock fell down”, according to the writing on the little wooden box, made to house the meteorite at a later stage.

Then, on the 11th August 2012, nearly 140 years later, amateur astronomer and former Director of the Eise Eisinga Planetarium in Franeker, Henk Nieuwenhuis, came across the rock as part of a collection belonging to a Mrs L. Kiers. “I really couldn’t believe my eyes,” remembers Mr Nieuwenhuis who straightaway recognised the rock as a carbonaceous meteorite. Mr Nieuwenhuis’ identification of this rock as a meteorite was later confirmed through research carried out by astronomer Niek de Kort of the Royal Netherlands Association for Meteorology and Astronomy (KNVWS) and geoscientists Marco Langbroek and Wim van Westrenen of the Vrije Universiteit (VU) of Amsterdam. Initially sceptical, the scientists became very excited as they realised that the rock was indeed an unrecognised Dutch meteorite.

Origin of life on earth

The Diepenveen discovery turns out to be very important internationally because of its unusual composition. It belongs to the relatively large class of so-called ‘stony meteorites’ but within this class, there is a rare sub-class known as ‘carbonaceous chondrites’, to which only about 1% of all meteorites belong, and the Diepenveen meteorite is one of these. Carbonaceous chondrites can contain complex molecules which may have played a role in the origin of life on earth. Analysis of a small piece of the Diepenveen has shown that it does indeed contain organic molecules but what those are exactly is now the subject of further research. Scientists at the Faculty of GeoSciences at the VU University of Amsterdam and Naturalis Biodiversity Center are writing various scientific publications about the Diepenveen meteorite, together with various international organisations.

The Diepenveen meteorite is extremely old, as old as the solar system which formed roughly 4.6 billion years ago. It weighs 68 grams.

History of the find

The researchers are also interested to know whether other bits of rock from around that time in 1873 are hidden away somewhere. So during the Christmas holiday, a day has been organised during which the inhabitants of Diepenveen will be asked whether they may have, perhaps somewhere in their attic, some material or documents that could shed some more light on this extraordinary discovery.

Scientific collection

In the meantime, on the 12th December 2013 at 11:30 a.m., the meteorite’s former owner, Mrs L. Kiers, presented the ‘Diepenveen’ to the Director of Naturalis Biodiversity Center, Edwin van Huis. As part of Naturalis' scientific collection, the rock will still be accessible for further research and it will also be officially included on the international list of meteorites. In exchange for the Diepenveen, Mrs Kiers will be given a piece from a similar sort of meteorite, ‘the Allende.’

Meteorite weekend in January

The Diepenveen, together with the four other Dutch meteorites, are on view to the public at Naturalis for just one weekend: the 18th and 19th January 2014. During that weekend, the scientists involved with this discovery will tell their story and hold a workshop called ‘How to recognise a meteorite.’ People can then also bring their own discoveries for examination by the experts. A detailed programme for this weekend will soon be available here (in Dutch).
More extensive background information about the Diepenveen and the other Dutch meteorites can be found here (in Dutch).

Quelle: Naturalis

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