Mystery meteorite found in Swedish quarry

The space rock offers a glimpse at the early solar system.

A Swedish limestone quarry turned up a rocky revelation: a new type of meteorite that may help astronomers reconstruct the history of the solar system.

Birger Schmitz from Lund University in Sweden and colleagues described the 470-million-year-old piece of space rock in Nature Communications in June.

The Thorsberg quarry in southern

Sweden had given up space rocks before – it is a rich source of L chondrite meteorites, thought to be debris from a collision between a large asteroid and another object. But evidence of the other half of that collision had never been found. Then, in 2014, workers noticed a strange dark grey smudge in the limestone layers, about eight centimetres long and 6.5 wide. After years of weathering, it didn’t look like a typical meteorite. But when analysing the different types (or isotopes) of oxygen and chromium in the rock, Schmitz and his team discovered it was unlike any other.

The strange bit of space detritus turned out to be an entirely new type of meteorite, which the research team named Oesterplana 065.

Phil Bland, astronomer and meteorite hunter at Curtin University in Western Australia, who wasn’t involved with the study says “We’ve found tens of thousands of meteorites on Earth,” “To find a completely new type – well, it’s fantastic.”

Schmitz’s team found that the meteorite’s age was within a million years of the age of chondrites from the quarry. It’s likely, they suggest, that the asteroid that spawned the fragment collided with the L chondrite’s parent asteroid, but it shattered into tiny pieces which would explain why the meteorite is – so far – one of a kind.

The team writes that Oesterplana 065 “may be the first documented example of an ‘extinct’ meteorite” – one whose parent asteroid has been completely destroyed.

Finding more bits of extinct meteorites and tracing which types fell on Earth – and when – will help astronomers to piece together clues about our solar system’s youth, the researchers write.

“There is potential to reconstruct important aspects of the solar system history by looking down in Earth’s sediments, in addition to looking up at the skies.”