Methane

Methane is a molecule consisting of one carbon and four hydrogen atoms, with the formula CH. It plays in important part in this story because it was one of the gases found on the young Earth, and so probably helped contribute towards the origin of life. You can still find methane on Earth today -- it is released by anaerobic bacteria in swamps, when it is called marsh gas. It is also found in coal mines, where it is a common cause of explosions. Methane also makes up more than half gas in natural gas, which is a major fuel in many countries.

Because it contains a carbon atom, when methane burns it creates carbon dioxide, which is a greenhouse gas. Therefore methane is not the perfect fuel.