Methane (CH₄)

A colorless, odorless greenhouse gas released by fossil-fuel operations, livestock, landfills, and wetlands. Satellites detect its concentration and can pinpoint large leaks.

Why it matters

Methane traps far more heat than carbon dioxide over the short term, so finding and fixing leaks is one of the fastest ways to slow warming — and satellites can spot big plumes operators may not even know about.

Where you’ll meet it

• EMIT on the ISS, built for mineral dust, also detects strong methane plumes with its imaging spectrometer.
• TROPOMI on Sentinel-5P maps global methane to flag regional hotspots.
• AIRS on Aqua contributes to long-term methane records in the atmosphere.

In plain terms

It’s like sniffing out a gas leak from orbit — methane is invisible and odorless to us, but the right sensor sees the plume rising from a pipeline or landfill.