Testing the survival of microfossils in artificial martian sedimentary meteorites during entry into Earth's atmosphere: the STONE 6 experiment

摘要: If life ever appeared on Mars, could we find traces of primitive embedded in sedimentary meteorites? To answer this question, a 3.5 billion-year-old volcanic sediment containing microfossils was the heat shield space capsule order to test survival rock and during entry into Earth's atmosphere (the STONE 6 experiment). The silicified from Kitty's Gap Chert (Pilbara, Australia) is considered be an excellent analogue for Noachian-age sediments. chert are also analogues potential martian life. An additional goal investigate living microorganisms (Chroococcidiopsis) protected by 2 cm thick layer whether endolithic organisms survive atmospheric when rocky coating. Mineralogical alteration due shock heating manifested formation fusion crust, cracks prograde retrograde changes α quartz β quartz, increase size fluid inclusions, dewatering hydromuscovite-replaced protoliths. carbonaceous matrix survived away crust but there maturity index kerogen towards crust. We conclude that kind can and, if it contains microfossils, they survive. were, however, completely carbonised flame leakage back sample therefore non-viable. However, using analytical model estimate temperature reached within thickness, that, even without leakage, probably need at least 5 shielded intense entry.