Enstatite chondrite
The enstatite chondrites (E-chondrites) are meteorites of a rare group of chondrites that contain the mineral enstatite .
They differ from the common and carbonaceous chondrites in that the iron component is almost only in a reduced , metallic form. This suggests that the original bodies of the E-chondrites, even if they are located in the asteroid belt today , were originally formed in a less oxygenated environment than the ordinary chondrites, i.e. not in the asteroid belt - like the ordinary chondrites - but in a shorter one Distance to the sun .
From measurements of the 53 Cr / 52 Cr ratio of chromium - isotopes of soil samples, Mars meteorites and HED-meteorites from the asteroid belt is concluded that the solar system , the 53 Cr / 52 increases Cr ratio with the distance to the sun. The 53 Cr / 52 Cr ratio of the enstatite chondrites would therefore indicate the formation of the enstatite original bodies at 1.4 astronomical units, just within the mean orbit of Mars (1.524 astronomical units).
Mohapatra and Murty (2003) conclude from a comparison of the isotopes of oxygen and nitrogen in Martian meteorites, common chondrites and enstatite chondrites that Mars accreted from material similar to the enstatite chondrites and the common chondrites in a ratio of 74:26 .
Depending on their metal content, the E-Chondrite in the groups EH ( H igh metal, having about 29% iron) or EL ( L divided ow metal, with about 22% iron).
Both groups are likely to come from a common body of origin. In the case of the EH4 meteorite from Abee (Canada) , the largest enstatite found at 107 kg, the planet Mercury is believed to be the original body, which is, however, controversial among experts.
Individual evidence
- ↑ A. Shukolyukov, GW Lugmair: On The 53mn Heterogeneity In The Early Solar System. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. Space Science Reviews, Vol. 92, No. 1-2, pp. 225-236, 2000
- ^ Ratan K. Mohapatra, SVS Murty: Precursors of Mars: Constraints from nitrogen and oxygen isotopic compositions of martian meteorites. Meteoritics & Planetary Science , Vol. 38, No. 2, pp. 179–323, 2003 ( short version ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and remove it then this note. )
- ↑ Photos and classification: Rumuruti Chondrite and Enstatit Chondrite.
literature
- Andrea Patzer: Noble gases in enstatite chondrites. Dissertation at the Geosciences Faculty of Johannes Gutenberg University in Mainz (pdf; 1.59 MByte)
