Evidence of panspermia: from astronomy to meteorites
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Abstract
The theory of cometary panspermia is tested in the wake of two reported falls in Tissint, Morocco
on July 18, 2011 and in the central province of Polonnaruwa, Sri Lanka on December 29, 2012.
Samples of the Tissint and Polonnaruwa stones were studied using a variety of laboratory
procedures and equipment including ICP-OES, GC-MS, SEM, EDAX, CHN, FTIR, Raman
Spectroscopy, XRD and Optical Spectroscopy.
Results of Tissint show the presence of several 5-50μm pyrite grains rimmed by a layer of reduced
organic carbon with graphitisation levels consistent with other Martian meteorites. A complex
precursor carbon inventory is demonstrated with peak temperatures ~ 250 OC and elemental ratios
typical of high volatility bituminous coals.
A theoretical model of the ecology of arsenic on early Mars is then developed and discussed
involving microbial reduction of Fe-oxides. This hypothesis is shown to be supported by SEM
observations of spherical chains of pits, with morphologies distinct from abiotic alteration features
but closely comparable to biologically mediated microstructures created by Fe- and S-oxidising
microbes.
The contribution of core-mantle grains to mid-IR emission features is then modelled using
extinction and scattering efficiencies for composite spheres based on the Guttler extension of the
Mie formulae. Results show that kerogen-pyrite grains closely adhere to observed 9-13μm emission
characteristics observed in the Trapezium nebula.
Results of studies on Polonnaruwa show a highly porous Si-K-rich, Al-depleted, amorphous melt
enclosing trace (commonly <1μm) anorthoclase, albite, anorthite and quartz. Bound H2O <
0.03wt% indicates origin from hypervelocity impact. SEM analysis revealed several fossil
microorganisms similar to acritarchs, hystrichospheres and diatoms.
Geologic age of the stones is determined by N/C atomic ratio depletion that indicate the presence of
embedded fossil remains that date back to at least ~300 Ma. Triple oxygen isotope analysis provide
values of Δ17O = - 0.335 with δ17O = 8.978 ± 0.050 and δ18O = 17.816 ± 0.100 that is shown to be
consistent with non-terrestrial sources.
Results are seen to substantially support the theory of cometary panspermia