Methane is a colorless, odorless gas made of carbon and hydrogen atoms. It's one of the simplest molecules in chemistry: just one carbon atom surrounded by four hydrogen atoms, which chemists write as CH₄.

Methane matters for two big reasons. First, it's an excellent fuel. Natural gas, which heats millions of homes and powers stoves, is mostly methane. When methane burns, it releases energy we can use for cooking, heating, or generating electricity. Second, methane is a powerful greenhouse gas: it traps heat in Earth's atmosphere much more effectively than carbon dioxide, though it doesn't last as long.

Nature produces methane in surprising ways. It bubbles up from wetlands and rice paddies where bacteria break down plants without oxygen. Cows and other livestock produce methane in their digestive systems. Even termites create small amounts. Scientists have found methane on Mars and Saturn's moon Titan, making it one of the few molecules we've discovered beyond Earth.

The challenge with methane is balance. We depend on it for energy, but when it escapes into the atmosphere from leaking pipelines or landfills, it contributes to climate change. That's why engineers work to capture methane from waste and prevent leaks, because the same molecule that warms our homes shouldn't warm our planet.