Atmosphere of Pluto by the spacecraft "New Horizons". The main component of the atmosphere of Pluto is nitrogen. Content of methane, according to measurements by "New Horizons", is 0.25%. For carbon monoxide, the Earth-based estimates are (2010) and (2015). Under influence of high-energy cosmic radiation, these gases react to form more complex compounds (not volatile at Pluto's surface temperatures), including ethane (CH), ethylene (CH), acetylene (CH), heavier hydrocarbons and nitriles and hydrogen cyanide (HCN) (amount of ethylene is about 0.0001%, and amount of acetylene is about 0.0003%). These compounds slowly precipitate on the surface. Probably, they also include tholins, which are responsible for
Atmosphere of Titan N is preferentially lost from the upper atmosphere under photolysis and heating. Because Titan's original N–N ratio is poorly constrained, the early atmosphere may have had more N by factors ranging from 1.5 to 100 with certainty only in the lower factor. Because N is the primary component (98%) of Titan's atmosphere, the isotopic ratio suggests that much of the atmosphere has been lost over geologic time. Nevertheless, atmospheric pressure on its surface remains nearly 1.5 times that of Earth as it began with a proportionally greater volatile budget than Earth or Mars. It is possible that most of the