Atmosphere of Triton Atmosphere of Triton The atmosphere of Triton is the layer of gases surrounding Triton. The surface pressure is only 14 microbars (0.014 hPa or 1 mmHg), of the surface pressure on Earth, and it is composed of nitrogen, similar to those of Titan and Earth. It extends 800 kilometers above its surface. Recent observations have shown an increase in temperature. Nitrogen is the main gas in Triton's atmosphere. The two other known components are methane and carbon monoxide, whose abundances are a few hundredths of a percent of that of the nitrogen. Carbon monoxide, which was discovered only in 2010
Atmosphere bodies within the Solar System have extremely thin atmospheres not in equilibrium. These include the Moon (sodium gas), Mercury (sodium gas), Europa (oxygen), Io (sulfur), and Enceladus (water vapor). The first exoplanet whose atmospheric composition was determined is HD 209458b, a gas giant with a close orbit around a star in the constellation Pegasus. Its atmosphere is heated to temperatures over 1,000 K, and is steadily escaping into space. Hydrogen, oxygen, carbon and sulfur have been detected in the planet's inflated atmosphere. Earth's atmosphere consists of a number of layers that differ in properties such as composition, temperature and pressure.