Atmosphere of Earth Atmosphere of Earth The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water
Atmosphere of Mars freezing point of water. With the higher temperature, running water could have carved out the many channels and outflow valleys that are common on the planet. It also might have gathered to form lakes and maybe an ocean. Some researchers have suggested that the atmosphere of Mars may have been many times as thick as the present one of Earth; however, research published in fall 2015 advanced the idea that perhaps the early Martian atmosphere was not as thick as previously thought. Currently, the atmosphere is very thin. For many years, it was assumed that as with Earth, most of