Molecular synthesis in hypervelocity impact plasmas on the primitive Earth and in interstellar clouds

Abstract

[1] When impact speeds exceed a critical range of $15-20 km s À1 , the resulting plasma plume energizes very rapidly from a few eV, to as high as 30-50 eV when speeds reach 50-100 km s À1, and can be completely atomized and ionized. During post-impact adiabatic dispersion, the degree of ionization drops. The remaining ion population is mostly atomic, sampling the elemental composition of the colliding bodies, but some molecular ions are also formed. We present here results of experiments in which the physical and chemical conditions in the plume of a hypervelocity micrometeorite impact well above 20 km s À1 were modeled with Q-switched laser ablation. The formed molecular ions were analyzed with a time-of-flight (TOF) mass reflectron capable of distinguishing plasma-synthesized from surfacedesorbed species. Singly-and multiply-charged small organic molecules were identified as having formed in laser plasmas induced from inorganic carbonaceous substances. The results show the possibility of abiogenic synthesis of organic molecules in hypervelocity impacts of meteors on the primitive Earth during heavy bombardment and of dust particles in interstellar clouds.

Conditions for the emergence of life on the early Earth: summary and reflections

“…The high-velocity (10-100 km s K1 ) impact of asteroids or comets, which initially contain prebiotic materials or building blocks of biomolecules, can result in the synthesis of amino acid oligomers (Bernstein 2006). It was experimentally demonstrated that hypervelocity impacts can oligomerize amino acid monomers (Blank et al 2001) and other large organic molecules (Miruma 1995;Managadze et al 2003). Furthermore, organic compounds can also survive such hypervelocity impacts (Pierazzo & Chyba 1999), providing favourable conditions for the exogeneous delivery of organic materials on Earth.…”

“…However, there is a distinct possibility that, in other molecular clusters, an impact-induced extreme compression will produce a metallic phase. In such transient metallic clusters, plasma produced by the high-temperature impact may be operative in relevant molecular syntheses (Managadze et al 2003).…”

“…The description of functional living matter requires a holistic conceptual framework, with some of its cornerstones being: (i) the ideas of Onsager & Morowitz (Folsome 1979) on complex matter, (ii) the implementation of the concepts of molecular information at the molecular and supramolecular level (Eigen 1971(Eigen , 1995(Eigen , 1996Yates 1987;Lehn 1988, Lehn 2002a,b, 2003Eigen & Winkler 1993;Taylor 2006) and (iii) the central role of self-organization (self-assembly), which leads to the evolution of a 'complex biological matter' (Eigen 1971(Eigen , 1995(Eigen , 1996Lehn 2002aLehn ,b, 2003Heckl 2004;Deamer 2006). A heuristic, highly speculative, partial scheme for the emergence of living matter in the 'parameter space' of increasing complexity could be as shown in Scheme 1.…”

Survival of Organic Materials in Hypervelocity Impacts of Ice on Sand, Ice, and Water in the Laboratory

“…A variety of experiments have shown organic synthesis during shock experiments (e.g., McKay and Borucki, 1997) or during hypervelocity impact-generated plasmas (Managadze et al, 2003a(Managadze et al, , 2003b. It is also possible to fire laser pulses into samples to induce shock effects, and Nna-Mvondo et al (2008) did this with ice targets doped with various materials.…”

Oxidation of carbon compounds by silica-derived oxygen within impact-induced vapor plumes

“…In both experiments and thermodynamic calculations, we consider reaction systems consisting of silica (SiO 2 ) and polyethylene (PE). First, we conduct LPV experiments, which have been used to simulate impact vaporization (e.g., Mukhin et al, 1989;Kadono et al, 2002;Managadze et al, 2003;Sugita et al, 2003;Ohno et al, 2004) and measure whether CO and/or CO 2 are produced in even carbon-poor reaction systems. We use artificial samples, mixtures of silica powder and polyethylene powder, for investigating the effect of silica-derived oxygen.…”