Earth: Why is it so nice? (… so “Habitable” for Life?) Our Atmosphere takes care of it!
Benefits of an Atmosphere: Heat Circulation (W E, & Poles Equator)
Benefits of an Atmosphere: Oxygen! (For Breathing – a Source of Energy – and a Sign of Life!)
Benefits of an Atmosphere: UV Protection from its “Ozone Layer”!
What Mars “Used to Be” (we believe…) (…before its Core Solidified, so its Magnetic Fields died away, and its Atmosphere was stripped by the Solar Wind, and the remaining Water Vapor & Carbon Dioxide froze over…)