我们已经了解的某些方面的要求需要对火星和月球。@David_Garcia_Bodego提到他的评论中,天体的重力是一个主要的因素能够保留一种氛围。这是因为一个天体的引力影响[逃逸速度][1]的身体。另一个重要因素是天体的表面温度。这就是为什么(泰坦)[2],土星的卫星有一个厚厚的大气层[3],尽管有一个类似的逃逸速度月球(月神),[冷得多,厚厚的大气层][4]。另一个因素帮助泰坦在维护厚厚的大气层是它距离太阳和较弱的影响(太阳风)[5]在那个距离。同时,泰坦是保护(土星磁层)[6]。我推荐阅读:[*会发生什么空气从月球表面释放吗?*][7]-[*月球保持氛围吗?*][8]和链接包含在这些问题。是的,这些问题讨论月球和火星,但这些问题中提供的信息适用于火星。 The [graph][9] below provides a visual of the gases a celestial body can retain in a atmosphere based on escape velocity and temperature. [![enter image description here][10]][10] Factors that act in favor of Mars being able to have a thick atmosphere are: - Mars is farther away from the Sun than Earth & Luna so it experiences a weaker solar wind. - The surface temperature of Mars is cold, which reduces the energy of atmospheric molecules. Factors that act against Mars being able to have a thick atmosphere are: - The gravity of Mars and subsequently the escape velocity of Mars is small. - The lack of a magnetosphere to shield the atmosphere from solar wind. [1]: https://en.wikipedia.org/wiki/Escape_velocity [2]: https://en.wikipedia.org/wiki/Titan_(moon) [3]: https://en.wikipedia.org/wiki/Atmosphere_of_Titan [4]: https://physics.stackexchange.com/questions/31909/why-is-titan-able-to-maintain-an-atmosphere-and-not-luna [5]: https://en.wikipedia.org/wiki/Solar_wind [6]: https://en.wikipedia.org/wiki/Magnetosphere_of_Saturn [7]: https://space.stackexchange.com/questions/39474/what-will-happen-to-the-air-released-from-the-moons-surface [8]: https://space.stackexchange.com/questions/12576/could-the-moon-keep-an-atmosphere/12588#12588 [9]: https://en.wikipedia.org/wiki/Atmospheric_escape [10]: https://i.stack.imgur.com/XlvLf.png