In the 1950s, geologists realized that a meteorite found near Wedderburn in Australia had a composition like no other. Decades later, scientists have found a mineral never before known naturally and the race continues to learn what this can tell us about a planet destroyed in the early days of the solar system.
What is the Wedderburn meteorite?
For decades, scientists have been trying to unravel its secrets, and today, we can say that they have solved another. The Wedderburn meteorite, found just northeast of the city in 1951, was a small 210-gram chunk of strange-looking space rock that fell from the sky. It has proportionally more nickel (24%) than any meteorite ever seen . In addition, it has an unusually high carbon concentration for an iron-nickel meteorite, although much lower than other types.
This composition alone suggests that the material was once part of a planet’s core. The expert, Stuart Mills, of Museums Victoria, has clarified that some of the minerals have confirmed it. Although it is rare that such rocks exist because, in the early days of the solar system, some partially formed planets smashed into each other so hard that they both broke apart, scattering fragments of their cores throughout the inner solar system. These elements, like the more common meteorites with less exotic origins, have been roaming space for 4.5 billion years before landing on Earth.
Why is this meteorite different?
Planetary scientists are eager to know why the Wedderburn meteorite has more nickel and carbon than its counterparts, and what this says about the planet it came from. Caltech researcher Chi Ma has further upped the stakes by finding an iron carbide with the formula Fe5C2 and a distinctive structure in the heart of the meteorite. The findings of this new study are detailed in the journal American Mineralogist .
At work, Ma has named the newly discovered mineral “ edscottite ” in honor of Professor Edward Scott, a meteorite expert and cosmochemist at the University of Hawaii.
The discovery of edscottite is really significant for science because until now it was not known if this atomic formation of iron carbide occurred naturally. The synthetic version of the mineral, however, was first seen decades ago as a stage during the smelting of iron (one of the phases that iron goes through when it is cast into steel)
Such confirmation is important, because it is a prerequisite for minerals to be officially recognized as such by the International Mineralogy Association (IMA).
Now, thanks to new analysis by Chi Ma and UCLA geophysicist Alan Rubin, edscottite is now an official member of the IMA mineral club, which is more exclusive than it sounds.
By tradition, minerals are only given a name when they are found in nature – humans have used many more ways to find elements than we discovered to exist naturally, so their formulas refer to those we create.
After losing much of its study material, the Wedderburn meteorite is so small (just 70 grams) that the museum no longer wants to cut its gemstone. Instead, he needs some of the plates taken in the 1950s, now scattered in labs around the world, to be returned, and he hopes these will satisfy planetary scientists looking for more natural edscottite.
As to how this splinter of natural edscottite ended up just outside Wedderburn, it cannot be known for sure, but according to planetary scientist Geoffrey Bonning of the Australian National University, who was not involved in the study, the mineral could have formed in the heated and pressurized core of an ancient planet , he tells The Age .
Long ago, this unfortunate edscottite-producing planet could have suffered some kind of colossal cosmic collision, with another planet, moon, or asteroid, and been destroyed, with the shattered fragments of this world thrown through time and space. Millions of years later, one of those fragments accidentally landed on Wedderburn. Things of the universe.
Referencia: Edscottite, Fe5C2, a new iron carbide mineral from the Ni-rich Wedderburn IAB iron meteorite. Chi Ma / Alan E. Rubin. merican Mineralogist Published Online: 2019-08-28 | DOI: https://doi.org/10.2138/am-2019-7102
