1 9.2720 Solutions for problem set 5 Mercury and the moon have extremely tenuous and transient atmospheres perhaps composed of captured solar wind particles. Earth has an atmosphere of composed of about nitrogen and oxygen. Venus s atmosphere is roughly 100x thicker than that of Earth and is motly carbon dioxide. Mars s atmosphere is about 100x thinner and is also CO2. Albedo is the fraction of incident light that is reflected.
Fresh snow has a high albedo, bare dirt has a low albedo.
IR is absorbed by CO2, H2O, CH4, NH3, etc. Ultraviolet light is absorbed mainly by ozone. Xrays are absorbed by various atoms in the upper atmosphere. The sky is blue because the particles in the air scatter blue light much more effectively than red light. So the blue seems to come from all around the sky.