Melosh H J, Vickery A M
Lunar and Planetary Laboratory, University of Arizona, Tucson 85721, USA.
Nature. 1989 Apr 6;338(6215):487-9. doi: 10.1038/338487a0.
Abundant geomorphic evidence for fluvial processes on the surface of Mars suggests that during the era of heavy bombardment, Mars's atmospheric pressure was high enough for liquid water to flow on the surface. Many authors have proposed mechanisms by which Mars could have lost (or sequestered) an earlier, thicker atmosphere but none of these proposals has gained general acceptance. Here we examine the process of atmospheric erosion by impacts and show that it may account for an early episode of atmosphere loss from Mars. On the basis of this model, the primordial atmospheric pressure on Mars must have been in the vicinity of 1 bar, barring other sources or sinks of CO2. Current impact fluxes are too small to erode significantly the present martian atmosphere.
火星表面存在大量河流作用的地貌证据，这表明在重轰炸期，火星的大气压力足够高，使得液态水能够在其表面流动。许多作者提出了火星可能失去（或封存）早期较厚大气层的机制，但这些提议均未得到广泛认可。在此，我们研究了撞击导致的大气侵蚀过程，并表明这可能是火星早期大气损失的一个原因。基于该模型，除非存在其他二氧化碳源或汇，火星原始大气压力必定在1巴左右。当前的撞击通量太小，不足以显著侵蚀目前的火星大气。
