37th DPS Meeting, 4-9 September 2005
Session 58 Galilean Satellites
Poster, Thursday, September 8, 2005, 6:00-7:15pm, Music Recital Room

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[58.10] Impact Driven Chemistry on Europa's Surface

B. N. Khare (SETI Institute), D. NNa Mvondo (National Research Council), J. G. Borucki (NASA Ames Ames Research Center), D. P. Cruikshank (NASA Ames Research Center), W. A. Belisle (Lockheed Martin), P. Wilhite (New York University), C. P. McKay (NASA Ames Research Center)

A new energy source for organic synthesis on simulated Europan surfaces, electrical discharge, light emission, and magnetic phenomena from impacts into the ice, has been studied [Borucki et al. J. Geophys. Res. 107 (E11) 5114 (2002)]. Part of the impactor's kinetic energy is converted into electrical potential. The mechanical disruption causes the release of energy as light, heat, and electrical and magnetic fields as secondary emissions that synthesizes complex organic material named tholin [Sagan and Khare, Nature 277, 102 (1979)] in the area of impact craters. The morphology of the impact craters indicates that tholin is the result of outflow from the fracture zone. Large pool of liquid water may exist for thousands of years as suggested for Titan [Thompson and Sagan, Eur. Space Agency Spec. Publ., ESA-SP, 338, 167 (1992)] and may also apply to Europa potentially driving prebiotic chemistry due to energy pumped in from the secondary emissions.

We have detected 8.8 ppm of H2O2 from impact of a 1/4" iron bullet at 5.3 km/s over water ice at ca. -100 C. H2O2 has been detected on the surface of Europa [Carlson et al., Science 283, 2062 (1999)]. Further confirmation by Raman Scattering at 874.5 cm-1 and IR absorbance at 2854 cm-1 is continuing. Since the impactor is limited in the number of experiments we can run, other experiments used a laser induced plasma (LIP) to shock ice mixed with ammonium sulphate and methanol. We detected CH4, CO, N2O, C2H6, CH3CN, CH3COCH3, HCOOCH3 (methyl formate), and traces of HCN. LIP on a mixture of water and methanol ice produced CH4, CO, HCHO, ethanol, formic acid methylester, propanol, acetone, dimethoxyme, and possibly ethanone-1phenyl or other phenyl group. NH3 and methanol could be delivered on impact of comets while sulfur expelled from Io.

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