The Wedderburn meteorite is named for the remote gold rush town of Wedderburn in the state of Victoria, Australia, where it was found in 1951.
The small, 210-gram (7.4 ounces) space rock is red and black and is deeply scarred from its million-year-plus journey to its final resting place on Earth. It is being held in a vault at the Museums Victoria collection. The space rock has been the focus of research and examination for decades – so much so that only one-third of the original specimen remains intact.
The rest of the meteorite was taken away in a series of slices to find out what the meteorite was made from. Over the years, analysis has revealed traces of gold and iron, along with rarer minerals such as kamacite, schreibersite, taenite, and troilite.
The latest discovery
A team of scientists from CalTech in California, led by Caltech mineralogist Chi Ma, managed to get their hands on a slice in 2018, to see if it contained any rare minerals.
Thinking about minerals, we know that a mineral is an arrangement of atoms in different shapes. Diamond, for example, is an arrangement of carbon atoms. Graphite in the tip of a pencil is carbon too – but arranged in a different structure.
Inside the Wedderburn meteorite, sandwiched between other layers of minerals, the researchers found a thin sliver of a new material. Under the microscope, it resembles tiny white crystals. The mineral is made up of iron and carbon atoms mixed together into a certain pattern. They named it edscottite, after Edward Scott, a pioneering cosmochemist at the University of Hawaii.
Edscottite is an iron carbide mineral. A synthetic version of Edscottite was previously known to occur during iron smelting, however, finding the distinct atomic formulation of iron carbide inside a piece of a meteorite means this is the first time Edscottite has been found in nature.
“This meteorite had an abundance of carbon in it. And as it slowly cooled down, the iron and carbon came together and formed this mineral,” says Dr. Stuart Mills, Museums Victoria’s senior curator of geosciences. “We have discovered 500,000 to 600,000 minerals in the lab, but fewer than 6000 that nature’s done itself,” says Mills.
Where did the meteorite come from?
The meteorite is believed to have come from an old planet, which no longer exists. As it blew apart, meteorites from its core got thrust out into space.
The Wedderburn meteorite was just one chunk of the debris from the blasted planet. It is believed the rock circulated in space for millions of years before being pulled into Earth’s gravitational force and landing in Australia.
This study was published in the journal American Mineralogist on August 28, 2019.
