Colonization of Neptune


Neptune is the farthest planet in the Solar System. Neptune is a gold ice giant. Colonizing Neptune won’t be possible for a long time, but like other gas giants, it might be possible to harvest resources from Neptune.


Physical properties

The diameter of Neptune is approximately 50 000 kilometres, which is about four timesthe diameter of the Earth. This makes Neptune the fourth largest planet in our Solar System. Neptune is most dense of the gas giants, and by mass, its the third largest planet. If Neptune would have a solid surface, the gravity would be a bit stronger than the gravity on the Earth.

Structurally, Neptune has a lot of common with Uranus. It has a core, that consists of silicates, nickel and iron. On top of the core, Neptune has a mantle which is composed mostly of water ice, ammonia and methane. Neptune has an atmosphere, which consists primarily of hydrogen, helium and methane.

Orbit and rotation

Neptune is the farthest planet in our Solar System. On average, Neptune is about 30 times as far from the Sun than the Earth is. One orbit around the sun takes Neptune approximately 165 years. Neptune has an axial tilt which is about equal to the one on Earth, which creates seasons on the planet. Like other gas giants, the rotation speed of the gases and liquids around the axle varies. On average, one rotation around the axle takes about 12 to 16 hours.


Neptune has 14 known moons. Most of them are very small, so preliminary plans for habitation have only been created for the largest one, Triton. Of all the objects orbiting around Neptune, Triton weights over 99.5 percent.


Neptune has an atmosphere, that consists of 80 percent of hydrogen and around 19 percent of helium. There are also traces of other gases, such as methane. Uranus and Neptune have very similar atmosphere, but still, the planets have a different shade of blue. It is though that one of the planets has some compound, that changes the shade of the atmosphere.


Because of the distance from the Sun, Neptune is a cold planet. Temperatures on Neptune are often under -200 °C. There are some areas in the atmosphere, where the temperature can be over the freezing point of water, but pressure in these places is unbearable for humans.



Neptune is a far away planet, and traveling there takes time. It took approximately 12 years for the Voyager 2 probe to reach the planet. With technological advancement, the travel can be done faster, but it will still take years, and months in the best case scenario.


Floating habitats could be built on Neptune, the same way that they could be built on other gas giants. Floating bases would float in a proper pressure without requiring a lot of energy. Cold temperatures and fast winds might be a problem, however.

Its possible that habitats won’t be built on Neptune for a long time, but its moons could serve as a location for bases. The temperatures on the moons are also low, but their lower gravity and solid surface could allow us to build bases there and effectively harvest resources on Neptune.


Most efficient way to produce energy on Neptune would be nuclear reactors, especially fusion reactors if they can be developed. Neptune has a lot of helium-3, which could be used to fuel fusion reactors.


Because of the distance, radio signals will take a long time to reach Neptune. One message between the Earth and Neptune takes approximately four hours to be delivered. Real-time communication wouldn’t be possible, and therefore, in case of problems, the colonisers would have to be able to solve them very independently.


Neptune has resources that could be useful in the future. It has large reserves of helium-3, that might be valuable if fusion reactors can be developed. When comparing to Jupiter and Saturn, Neptune has a weaker gravity, which makes transport of the resources back to Earth a bit more inexpensive.


Neptune is a gas giant, so terraforming it wouldn’t be practically possible. If it will be used to harvest resources, it might be possible that after thousands of years only the rocky core is left. Around this rocky core, we could try to build an atmosphere and heat up the planet with mirrors, for example. However, with current technology, terraforming the planet is totally out of the question.


Neptune is a gas giant that resembles Uranus in many ways. Its a cold planet, whose conditions and distance from the Sun make it a challenging place to colonise. Neptune won’t be colonized for a long time.

Neptune has large resources of hydrogen and helium-3, which may be even more important in the future than they are now. Even though Neptune is farther from the Earth than the other gas giants, its lower gravity might make it more interesting target for resource harvesting than Jupiter or Saturn.