Early in the Solar System's history, energetic collisions of differentiated bodies affected the final composition of the terrestrial planets through partial destruction. Enstatite chondrites (EC) are the best candidates to represent the primordial terrestrial precursors as they present the most similar isotopic compositions to Earth. Here we report that collisional erosion of >15% of the early ...

Extensive collection efforts in Antarctica and the Sahara in the past 10 years have greatly increased the number of known meteorites. Groupings of meteorites according to petrologic, mineralogical, bulkchemical, and isotopic properties suggest the existence of 100–150 distinct parent bodies. Dynamical studies imply that most meteorites have their source bodies in the main belt and not among the...

Interstellar matter is known to be strongly irradiated by radiation and several types of cosmic ray particles. Simulated interstellar matter, such as forsterite Mg2SiO4, enstatite MgSiO3 and magnesite MgCO3 has been irradiated with the Co gamma-rays in liquid nitrogen, and also irradiated with fast neutrons at 10 K and 70 K by making use of the low-temperature irradiation facility of Kyoto Univ...

We discuss in detail a model which makes definite predictions for the fractionation of isotopes in sputtered material. The fractionation patterns can be nonlinear, and the pattern for a particular set of isotopes depends on the chemical matrix within which those isotopes are contained. Calculations are presented for all nonmonoisotopic elements contained in the minerals perovskite, anorthite, a...

Fracture behavior via a flexural test for newly found CaO–Al2O3–SiO2 (CAS) glass-ceramic (GC) was compared with that of enstatite GC and mica GC, which are well-known GCs high-fracture toughness machinability, respectively. By focusing on the nonelastic load–displacement curves, CAS characterized as less brittle material similar to machinable showed higher fracture toughness, KIC. The microcrac...