Locality: In perchloric acid-resistant residues of three ordinary chondrite meteorites (Adrar 003 [LL3.2], Inman [L3.4] and Tieschitz [H3.6]) and one enstatite chondrite
meteorite (Indarch [EH4]).
The new mineral, dubbed "Wassonite," was discovered inside the Yamato 691 enstatite chondrite
meteorite by American researchers from NASA as well as scientists from Japan and South Korea.
Dauphas thinks that Theia and the proto-Earth assembled from the same material, a geochemical mix of stuff found in meteorites called enstatite chondrites
. These meteorites have isotopic compositions very similar to those of Earth and the Moon and therefore might have formed in the same region of the protosolar disk.
The main subclass of these non-metallic stony meteorites (called chondrites as a category) that is thought to have made up Earth is called enstatite chondrites
. The discovery of another subclass, called CI chondrites, in a few places around the world, led scientists to think Earth formed essentially those two types of stony meteorites.
This composition is similar to that expected from partial melts of enstatite chondrites
, a rare type of meteorite that formed at high temperatures in highly reducing (low oxygen) conditions in the inner solar system.
Scientists had thought that most of the bodies that merged to make Earth formed from a narrow zone in space and were similar to each other, belonging to a subclass of meteorites called enstatite chondrites. This idea was based on measurements of numerous striking similarities between different types of atoms (called isotopes) of elements such as oxygen, nickel and chromium, between the Earth and enstatite chondrites.
They compared these to meteorite samples, particularly enstatite chondrites and another type called enstatite achondrites.
But M asteroids also mimic the spectra of silicate-dominated, metal-poor meteorites called enstatite chondrites
. The new satellite--designated S/2001 (22) 1 for now--will be a powerful tool for deciding between these possibilities; determining its orbit accurately will yield Kalliope's mass and, in turn, its density.
This spectrum was then compared with that of meteorites found on Earth that have been extensively studied in the laboratory and only one type of meteorite, enstatite chondrites, was found to have properties that matched Lutetia over the full range of colours.
Enstatite chondrites are known to be material that dates from the early Solar System, and they are thought to have formed close to the young Sun and to have been a major building block in the formation of the rocky planets, in particular the Earth, Venus and Mercury.
Planetary scientists further classify chondritic IDPs according to the degree of their oxidation, yielding carbonaceous, ordinary, and enstatite chondrites
. The carbonaceous-chondrite particles are almost completely oxidized and, as their name implies, quite rich in carbon.