how is the atmosphere there?
It has a tenuous nitrogen atmosphere, with trace amounts of carbon monoxide and small amounts of methane near its surface.
Triton (moon)
Triton has a tenuous nitrogen atmosphere, with trace amounts of carbon monoxide and small amounts of methane near its surface. 
how are saturn's moon titan and neptune's triton similar Both of them are geologically active. who discovered the triton? William Lassell. when was it discovered? 10 October,1846. can you mention some physical characteristics of this natural satellite? Triton's crust consists of 55% nitrogen ice with other ices mixed in. Water ice comprises 15–35% and frozen carbon dioxide the remaining 10–20%. Its surface area is 23 million km.
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Triton (moon) [SEP] Atmosphere
Triton has a tenuous nitrogen atmosphere, with trace amounts of carbon monoxide and small amounts of methane near its surface. Like Pluto's atmosphere, the atmosphere of Triton is thought to have resulted from evaporation of nitrogen from its surface. Its surface temperature is at least because Triton's nitrogen ice is in the warmer, hexagonal crystalline state, and the phase transition between hexagonal and cubic nitrogen ice occurs at that temperature. An upper limit in the low 40s (K) can be set from vapor pressure equilibrium with nitrogen gas in Triton's atmosphere. This is colder than Pluto's average equilibrium temperature of .