Atmosphere Atmosphere An atmosphere (from Modern Greek ἀτμός "(atmos)", meaning 'vapour', and σφαῖρα "(sphaira)", meaning 'sphere') is a layer or a set of layers of gases surrounding a planet or other material body, that is held in place by the gravity of that body. An atmosphere is more likely to be retained if the gravity it is subject to is high and the temperature of the atmosphere is low. The atmosphere of Earth is composed of nitrogen (about 78%), oxygen (about 21%), argon (about 0.9%) , carbon dioxide (0.03%) and other gases in trace amounts. Oxygen is used by most organisms
Atmosphere of the Moon on the order of just a few protons per cubic centimeter, it is virtually a vacuum in comparison with the atmosphere of the Earth. The Moon may also have a tenuous "atmosphere" of electrostatically-levitated dust. See Moon dust for more details. In October 2017, NASA scientists at the Marshall Space Flight Center and the Lunar and Planetary Institute in Houston announced their finding, based on studies of Moon magma samples retrieved by the Apollo missions, that the Moon had once possessed a relatively thick atmosphere for a period of 70 million years between 3 and 4 billion years ago. This