Xenomict energy in cold solids in space
- 58 Downloads
Minerals on earth whose crystalline order has been reduced by radioactive decay of contained atoms are termed “metamict.” They are rare and few because in most crystalline solids, atoms and vacancies are relatively mobile at terrestrial temperatures, and radiation damage tends to be self-annealing. This is not the case in the extreme cold of deep space. Below roughly 100 K, reduced vacancy mobility allows cosmic ray and solar wind induced lattice defects to endure and accumulate for eons, reaching energy densities of up to MJ kg−1 in some materials. We examine the possible effects of the release of energy stored in cold deep-space materials when solid-state defects recombine upon warming due to impacts, gravitational infall, or perihelion. Dimensional analysis suggests energetic defect recombination in radiation-damaged “xenomict” solids in comets, and planetesimals may, in some circumstances, raise internal temperatures enough to melt ice and volatilize frozen gases. We speculate that this may account for some cometary outbursts and Deep Impact experiment results. Calorimetric experiments on appropriately irradiated natural and synthetic materials are needed to further quantify these mechanisms.
KeywordsSolar Wind Carbonaceous Material Cometary Nucleus Lunar Regolith Pyrroloquinoline Quinone
R.S. acknowledges support from The Kurzweil Foundation. J.C.R. and M.I.P. appreciate partial support from NASA grants NAG5-12814 and NNG05GI66G to the Smithsonian Astrophysical Observatory. R.S. thanks NASA for the excellent fireworks preceding Dr. Frederick Seitz’ 95th birthday.
- Cox JD, Wagman DD, Medvedev VA (1986) CODATA key values for thermodynamics. Hemisphere, New YorkGoogle Scholar
- Devanathan R, Weber WJ, Boatner LA (1998) Response of zircon to electron and Ne+ irradiation. Mater Res Soc Symp Proc 481:419–424Google Scholar
- Gottstein G (2004) Physical foundations of materials science. Springer, Berlin Heidelberg New YorkGoogle Scholar
- Krueger FR, Werther W, Kissel J, Schmid ER (2004) Assignment of quinone derivatives as the main compound class composing interstellar grains based on both polarity ions detected by the cometary and interstellar dust analyser (CIDA) onboard the spacecraft STARDUST. Rapid Commun Mass Spectrom 18:103–111CrossRefPubMedGoogle Scholar
- Kurath SF (1957) Energy storage in metamict minerals. Am Mineral 42:91–99Google Scholar
- Seitz F, Vogt E, Weinberg AM (1998) Eugene Paul Wigner. Biogr Mem Natl Acad Sci 74:374–388Google Scholar
- Wunnemann K, Collins GS, Melosh HJ (2005) Numerical modeling of the Deep Impact mission experiment. Lunar Planet Sci 36:1837Google Scholar