atmosféras

Atmospheres refer to the layers of gases that surround a celestial body, such as a planet or moon. These gaseous envelopes are held in place by the gravitational pull of the body. The composition and thickness of an atmosphere can vary greatly depending on the celestial body's size, mass, temperature, and presence of a magnetic field.

For Earth, the atmosphere is crucial for life. It provides the air we breathe, protects us from harmful solar radiation, and regulates temperature through the greenhouse effect. Earth's atmosphere is primarily composed of nitrogen (about 78%) and oxygen (about 21%), with smaller amounts of argon, carbon dioxide, and trace gases. It is divided into several layers, including the troposphere, stratosphere, mesosphere, thermosphere, and exosphere, each with distinct temperature and pressure characteristics.

Other planets possess atmospheres with diverse properties. For instance, Venus has an extremely dense atmosphere rich in carbon dioxide, leading to a runaway greenhouse effect and scorching surface temperatures. Mars has a thin atmosphere, also mostly carbon dioxide, offering little protection from radiation and resulting in very cold conditions. Gas giants like Jupiter and Saturn have massive atmospheres primarily composed of hydrogen and helium. The study of atmospheres, known as atmospheric science or meteorology, helps us understand weather patterns, climate change, and the potential for life on other worlds.