Researchers have reported a new mineral has been found in a meteorite that fell to Earth from the Moon. The mineral was formed on the Moon by repeated bombardments from meteorites and other space debris. It then ended up on Earth, where it was found in a meteorite in 2000 in the Dhofar region of Oman.
The new mineral was named hapkeite, after Bruce Hapke, an emeritus professor of geology and planetary sciences at Cornell University in New York, who predicted its discovery some 30 years ago.
Airless bodies such as the Moon, Mercury and asteroids have an inorganic soil made of crushed rocks called regolith.
In theory, space regolith is formed by the impact of micrometeorites up to 150 micrometres in size travelling at speeds of up to 100,000 kilometres per hour.
The heat from their impact melts and vaporises metals, which are then redeposited on rock fragments as tiny, scattered beads in a glassy coating. The mineral hapkeite was made when iron and silicon was deposited with two parts iron and one part silicon (Fe2Si), the researchers said.
And when they used a very precise synchrotron laser to look at the mineral's crystal structure, they found it was similar to the structure of synthetic Fe2Si. The scientists also found other phases of the mineral, which would have been formed at different pressurus and temperatures, inform abc.net.au
Some people called Bruce Hapke crazy when he proposed that micrometeorites no bigger than grains of sand were pummelling the moon's surface and vaporizing tiny bits of its rocky soil.
But the University of Pittsburgh scientist's prediction three decades ago that the vaporized iron and other minerals could condense as a glassy coating on surrounding soil has since been confirmed. And the latest evidence is inside a golf ball-size lunar meteorite.
That meteorite contains a new mineral, a vapor-deposited combination of iron and silicon that geoscientist Lawrence Taylor of the University of Tennessee has named "hapkeite."
Vindication is better late than never, said Hapke, a planetary scientist who attained emeritus status at Pitt in 2001. As for having a mineral named for him, "I was very pleased, needless to say," reports post-gazette.com