The major component of the atmosphere on Venus and Mars.
Atmosphere: The atmosphere is a thick blanket of air that is formed of various layers. It envelops a planetary body and is tethered to its position by the gravitational energy of the planet.
The atmosphere of Venus: The air of Venus is extremely hot and thick. It is composed of 96% carbon dioxide by volume and hence is extremely unsuitable for human life. The remaining is taken up by nitrogen.
The atmosphere of Mars: The air of Mars is thin and cold. It is formed of 95% carbon dioxide by volume. The remaining is occupied by diatomic nitrogen.