A planetary atmosphere is a layer of gases surrounding a planet, held in place by the planet's gravity. These gases can include nitrogen, oxygen, carbon dioxide, and other elements, depending on the planet. The atmosphere plays a crucial role in regulating temperature, protecting the surface from harmful radiation, and supporting weather patterns. Different planets have unique atmospheres. For example, Earth has a breathable atmosphere rich in oxygen and nitrogen, while Mars has a thin atmosphere mostly composed of carbon dioxide. Jupiter, a gas giant, has a thick atmosphere with swirling clouds of ammonia and water vapor, creating intense storms like the famous Great Red Spot.