Scientists expect to find a vast range of organic compounds in some of the planets, moons and comets of the outer Solar System, and the range of possible uses is even wider. For example, methane can be used as a fuel (burned with non-terrestrial oxygen), or as a feedstock for petrochemical processes such as making plastics. And ammonia could be a valuable feedstock for producing fertilizers to be used in the vegetable gardens of orbital and planetary bases, reducing the need to lift food to them from Earth.