Uranus is one of our Solar Systems four large gas giants. By size, it is the third largest, and by mass, it is the fourth largest planet in our vicinity. Uranus might be able to offer humankind useful resources, but colonizing it might be quite hard.
The diameter of Uranus is about 51 000 kilometres, which is about four times the diameter of Earth. By mass, Uranus is almost 15 times as large as Earth. Uranus is not a very dense planet, and of the planets in our Solar System, only Saturn is less dense. Gravity at the point in Uranus’ atmosphere, where the pressure is equal to Earths at sea level, is about 89 % that of experienced on Earth.
Uranus has a small core, which is comprised mostly of silicates, iron and nickel. Uranus has a very dense liquid mantle, which main components are water, ammonia and methane. When going upwards from the mantle, it changes gradually to its atmosphere, which consists of water, helium and ammonia. Uranus has a magnetic field, which is probably caused by its large, liquid mantle.
Orbit and rotation
The orbit of Uranus is located about twenty times farther from the Sun than Earths. One year in Uranus lasts about 84 years on Earth. Uranus rotates around its body in approximately 17 hours. However, because Uranus is a gas giant, the rotation speed for all parts is not equal. For example, the atmosphere at the equator rotates around the axis in about 14 hours.
The axis of Uranus has an extreme tilt. What this means, is that the north and south pole of Uranus experience a period of 42 years of darkness, and after that, 42 years of constant sunlight. This might cause some problems regarding the colonization of Uranus, but at the moment it’s not a main concern.
Uranus has 27 known moons. Five of the largest moons (Ariel, Miranda, Oberon, Titania and Umbriel) can be interesting objects with human colonization in mind. Currently, little is known of these moons. They probably consist of mostly equal parts of rock and ice. Largest of the moons, Titania, is the 8th largest moon in the Solar System.
Uranus doesn’t have a specific surface, as it is a gas giant. The surface of Uranus can be defined as a point where the mantle changes to atmosphere. However, as the change between mantle and atmosphere happens gradually, it’s hard to define.
Atmosphere of Uranus consists mainly of hydrogen, which is about 83 % of the atmosphere. 15 % of the atmosphere consists of helium and 2 % consists of methane. In addition, there are trace amounts of other gases, such as ammonia, ethane, acetylene and carbon dioxide. The blueish colour of Uranus is caused by methane, which absorbs the red spectrum of light and reflects the blue spectrum.
Uranus is one of the coldest objects in our Solar System. The coldest temperatures measured were as low as -225 °C. On average, the temperature where the pressure is about equal to Earths sea level, is about -200 °C. Uranus has a wide variety of weather phenomenoma, such as clouds and fast winds.
The time it takes to transport humans to Uranus is affected by many factors. With traditional technologies, the travel time is quite long. For example, it took almost ten years for Voyager 2 probe to reach Uranus. A newer probe, New Horizons, passed Uranus after about five years of flight. Return-trip to Uranus could take ten years, which is quite a long period for humans. In the future, the trip time might be shortened by technological advancement.
Building habitats on Uranus will be extremely difficult. Coldness and other factors make it inhospitable to life as we know it. According to some suggestions, floating bases could be built on Uranus, but the problems, such as cold temperatures and fast winds would still persist.
When reaching for resources of Uranus, it might be a good idea to build a base on some moon of Uranus. This moon could be used as a point to mine resources from Uranus. The moons would have a solid surface to build a base on, though the cold temperatures would still pose a problem.
Uranus is located far from Sun, so using solar power is probably out of the question. The best way to satisfy the energy needs of a settlement would be to use nuclear power. If fission reactors would be used, the fuel could be brought from Earth. If fusion reactors become usable one day, Uranus contains a lot of helium-3, which can be used as a fuel in those reactors.
Uranus is located far from the Sun and the Earth, so communications would be hindered by long delay. When planets are closest to each other, but still 2.6 billion kilometres apart, a radio signal would be delivered in about two and a half hours. When the planets are the furthest from each other, messages would take almost three hours to deliver. This makes real-time communication between the planets impossible.
Uranus is an interesting planet because of the resources it could possibly provide for humankind. Helium-3, which Uranus has plenty of, might be a valuable resource in the future, as it could be used as fuel in fission reactors. Also, the hydrogen that can be found on Uranus could be used to manufacture rocket fuel for spaceships. However, it is possible, that at the time we reach Uranus, rocket fuel is obsolete technology.
When comparing to other gas giants, such as Jupiter and Neptune, the good side of Uranus is its weaker gravity. Collecting resources would be easier and transporting them away would be cheaper. Because of this, it is estimated that Uranus and Neptune might be more important sources for resources than the larger gas giants.
Uranus is a large and cold gas giant, that is located quite far from Earth. Colonizing Uranus won’t be possible for a long time, because of all the challenges the colonization poses. However, if we manage to develop the technology needed, Uranus might be an important resource well for the humankind in the future.