PlanetStar Wiki

This is what ammonia planet may look like

Ammonia planet is an assumed class of planet with surface covered in lakes or oceans of ammonia with ammonia clouds in the atmosphere.


Viewed from space, ammonia oceans would usually appear dark brown due to large amounts of alkaline earth metals dissolved in it. Although ammonia oceans would appear blue in absent or small amounts of alkali earth metals dissolved in it. The lands appear blackish due to black vegetation.

Atmosphere and climate[]

Ammonia planets tend to have similar climates to Earth's, except it uses ammonia as a "variable gas" instead of water vapor as it is on Earth. For example, there are ammonia rain or ammonia snow instead of water rain or water snow. Those planets tend to be very cold, at around −150°F (−115°C), or warmer depending on the thickness of the atmosphere. Their atmospheres tend to be composed mostly of nitrogen (N2) and oxygen (O2 with variable amounts of ammonia (NH3) and trace amounts of carbon dioxide (CO2) and other gases.


The life-bearing status on ammonia planets are fair. Life on ammonia planets are strange that they can adapt to extreme cold and use ammonia as a solvent, whereas life on Earth use water as a solvent. Some of the plants on ammonia planet use photosynthesis using light from the parent star while others perform chemosynthesis. It is predicted that plants use ammonia (NH3) and carbon dioxide (CO2) to produce methylamine (CH3NH2), nitrogen (N2), and oxygen (O2) using the balanced equation below:

10 NH3 + 3 CO2 + energy → 6 CH3NH2 + 4 N2 + 3 O2.

It is also predicted that animals inhale oxygen and exhale carbon dioxide for respiration, just like animals here on Earth. Animals also eat foods rich in amines and drink liquid ammonia. The main biogeochemical cycle on ammonia planets is the ammonia cycle compared to the carbon cycle here on Earth.

However, life on some ammonia planets may not be carbon-based, but silicon-based as they have better survivability to extreme cold than carbon-based life.


There are an estimated 24 billion ammonia planets in our galaxy alone, more than half as abundant as methane planets. They make up 4.6% of all 524 billion terrestrial planets and 2.9% of all 820 billion planets in our galaxy.

Related links[]