| タイトル | Transient Climate Effects of Large Impacts on Titan |
| 本文（外部サイト） | http://hdl.handle.net/2060/20140010854 |
| 著者（英） | Korycansky, Donald; Nixon, Conor A.; Zahnle, Kevin J. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2013-05-20 |
| 言語 | eng |
| 内容記述 | Titan's thick atmosphere and volatile-rich surface cause it to respond to big impacts in a somewhat Earth-like manner. Here we construct a simple globally-averaged model that tracks the flow of energy through the environment in the weeks, years, and millenia after a big comet strikes Titan. The model Titan is endowed with 1.4 bars of N2 and 0.07 bars of CH4, methane lakes, a water ice crust, and enough methane underground to saturate the regolith to the surface. We find that a nominal Menrva impact is big enough to raise the surface temperature by approx. 80 K and to double the amount of methane in the atmosphere. The extra methane drizzles out of the atmosphere over hundreds of years. An upper-limit Menrva is just big enough to raise the surface to water's melting point. The putative Hotei impact (a possible 800-1200 km diameter basin, Soderblom et al., 2009) is big enough to raise the surface temperature to 350-400 K. Water rain must fall and global meltwaters might range between 50 m to more than a kilometer deep, depending on the details. Global meltwater oceans do not last more than a few decades or centuries at most, but are interesting to consider given Titan's organic wealth. Significant near-surface clathrate formation is possible as Titan cools but faces major kinetic barriers. |
| NASA分類 | Lunar and Planetary Science and Exploration |
| レポートNO | GSFC-E-DAA-TN9815 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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