Yet methane clouds, high methane humidity, and obvious cutting of river valleys in the icy surface spoke of methane cycling on Titan much the way water cycles from lakes and oceans to clouds and rain on Earth.
Methanotrophs involved in the global methane cycle consume methane as their sole source of carbon and energy for growing 58 whereas methanogens can obtain energy for growth by converting a limited number of substrates to methane.
But "to really get a handle" on Titan's methane cycle, they'll need to monitor the exchange of methane between the lakes and the atmosphere.
Its atmosphere contains methane -- so much of it that scientists have thought that Titan might have a methane cycle, analogous to Earth's water cycle, in which methane evaporates, condenses and precipitates.
Titan has an atmosphere, composed, like Earth's, mostly of nitrogen, and some planetary scientists think it may have a methane cycle, like the Earth's water cycle with its clouds, rain and seas.
The distribution of methane on the Siberian Arctic shelves: implications for the marine methane cycle.
So, the researchers suggest, Titan may indeed have a methane cycle.
The location of the clouds at the south pole makes sense, because Titan was near the start of its seven-year-long summer and the pole was in full sunlight, creating enough heat to drive the methane cycle.
From cows to wetlands to rice paddies [as well as other sources], the methane cycle is harder".
More specifically, identification of the diverse organisms responsible for the oxidation of methane within various environments will help to better understand the key players involved in the methane cycle and evaluate their potential effectiveness as a biological methane filter.
