The gases that surround Earth or another planet are collectively referred to as the atmosphere. The composition and characteristics of an atmosphere can vary widely from one celestial body to another.
Earth's Atmosphere
Earth's atmosphere is composed primarily of the following gases:
- Nitrogen (N2): Approximately 78%
- Oxygen (O2): About 21%
- Argon (Ar): Around 0.93%
- Carbon Dioxide (CO2): Approximately 0.04%, but this can vary due to human activities and natural processes.
- Trace gases: Including neon, helium, methane, krypton, and hydrogen, among others.
The Earth's atmosphere also contains water vapor, which is variable but can make up about 0% to 4% of the atmosphere, influencing weather and climate.
Atmospheres of Other Planets
- Mars: Thin atmosphere, mostly carbon dioxide (about 95.3%), with nitrogen (2.7%) and argon (1.6%).
- Venus: Thick atmosphere, mainly carbon dioxide (96.5%), with nitrogen (3.5%) and traces of sulfuric acid clouds.
- Jupiter: Composed mainly of hydrogen (around 90%) and helium (about 10%), with trace amounts of methane, ammonia, and other gases.
- Saturn: Similar to Jupiter, with a high percentage of hydrogen and helium, along with trace gases.
- Titan (Saturn's Moon): Dense atmosphere mostly composed of nitrogen, with methane and hydrogen.
Significance
The atmosphere plays a crucial role in supporting life on Earth, regulating temperature, protecting from harmful solar radiation, and contributing to weather and climate systems. Understanding the atmospheres of other planets helps scientists learn about their potential for life, meteorological phenomena, and overall geological activity.