A terrestrial planet with a thin atmosphere, Mars has surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts and polar ice caps of Earth.

• 地面星球与薄的气氛中，火星表面特征想起这两个冲击环形山的月亮与火山，峡谷，沙漠和极地冰盖的地球。