Department of Earth Sciences/Physics and Astronomy, 1151 Richmond St., University of Western Ontario, London, Ontario, N6A 5B7, Canada.
California Institute of Technology, Mail code 100-23, Pasadena, CA 91125, USA.
Curr Issues Mol Biol. 2020;38:75-102. doi: 10.21775/cimb.038.075. Epub 2020 Jan 22.
Asteroid and comet impacts are known to have caused profound disruption to multicellular life, yet their influence on habitats for microorganisms, which comprise the majority of Earth's biomass, is less well understood. Of particular interest are geological changes in the target lithology at and near the point of impact that can persist for billions of years. Deep subsurface and surface-dwelling microorganisms are shown to gain advantages from impact-induced fracturing of rocks. Deleterious changes are associated with impact-induced closure of pore spaces in rocks. Superimposed on these long-term geological changes are post-impact alterations such as changes in the hydrological system in and around a crater. The close coupling between geological changes and the conditions for microorganisms yields a synthesis of the fields of microbiology and impact cratering. We use these data to discuss how craters can be used in the search for life beyond Earth.
小行星和彗星撞击已知会对多细胞生命造成深远的破坏，但它们对微生物栖息地的影响却知之甚少，微生物占地球生物量的大部分。特别有趣的是撞击点及其附近目标岩石的地质变化，这些变化可以持续数十亿年。研究表明，深部地下和地表微生物从岩石的撞击诱导破裂中获得优势。而岩石中孔隙的撞击诱导封闭则与有害变化有关。在这些长期的地质变化之上，还有撞击后在撞击坑内和周围的水文系统的变化等。地质变化和微生物条件之间的紧密耦合产生了微生物学和撞击坑形成领域的综合。我们利用这些数据来讨论如何利用陨石坑来寻找地球以外的生命。
