methane could be produced by microbes on Mars, too, if they exist in enough numbers.
methane (chemical formula CH4) is one of the simplest hydrocarbons, which literally means “containing hydrogen and carbon.”
Soot, methane, ozone, and HFCs are a lot less sexy than flying to Rio and making bold promises.
methane meth·ane (měth'ān')
An odorless, colorless, flammable gas that is the major constituent of natural gas and is used as a fuel and as an important source of hydrogen. Also called marsh gas.
A colorless, odorless, flammable gas that is the simplest hydrocarbon. It is the major constituent of natural gas and is released during the decomposition of plant or other organic compounds, as in marshes and coal mines. Methane is the first member of the alkane series. Chemical formula: CH4.