Colonization of Io


Io is one of the four large moons of Jupiter. Io is different from the other large moons, because it has volcanic activity. This makes the colonization attempts harder, and therefore Io won’t probably be colonized for a long time.


Physical properties

The diameter of Io is about 3 640 kilometres, which makes it a bit larger than the Moon. The mass of Io is about 1.5 percent of the mass of the Earth, and gravity experienced is about 18 % of the gravity experienced on Earth. With our current knowledge, we do not know if this is large enough to mitigate the problems associated with low gravity.

Io is different from the other moons of Jupiter, as it resembles more of a planet. It probably has an iron core, which are surrounded by a mantle and a crust, which both consist mostly of silicates. Io is volcanically a very active object. Volcanic activity also interacts with the magnetic field of Jupiter, and makes the magnetosphere twice as large.

Orbit and rotation

Of the large moons of Jupiter, Io orbits Jupiter the closest. It orbits around Jupiter in just under two days, which is twice as fast than the orbit of Europa and four times faster than the orbit of Ganymede. Io is inside the magnetosphere of Jupiter, and it is exposed to heavy radiation.


Io has a huge amount of volcanoes, and it is the most volcanically active object in the Solar System. The surface consists mostly of frozen lava, which contains a lot of sulfur and sulfur dioxide. There are a very few craters on the surface. The color of the surface varies, depending on the different composition of the lava.


Io has a thin atmosphere, that consists mostly of sulfur dioxide. There are also trace amount of other substances, such as sulfur oxide and oxygen. The atmosphere isn’t thick enough to be useful for humans. The atmosphere might actually be dangerous, as it is rich in sulfur.


Like other moons of Jupiter, Io is quite cold place. The temperatures vary between -180 °C and -140 °C, the average temperature being around -160 °C.



The travel time to Io is about equal, as to the other moons of Jupiter. If we use the same plans, as NASA has calculated for Callisto, we can expect that a round-trip within few decades would last four or five years. With advances in spacecraft propulsion, the trip could be done faster.


Properties of Io are not very suitable for human life. The largest problem are cold temperatures, high volcanism and large amounts of radiation. High volcanism could, in the worst case, destroy all settlements. Ideally, a base would be built under the surface, in an area where lava flows are not common. This would also help against the cold temperatures and space radiation.


Geothermal energy could probably be used on Io. Using geothermal energy in a large scale could be too expensive, so nuclear fission could also be used, instead. Because of the distance from the Sun, using solar energy wouldn’t be very efficient.


Radio messages will be delivered to Io in about the same time, as they will be delivered to Jupiter and its other moons. The messages will be delivered from half an hour to an hour. There might be cutoffs in communications, if the Sun or Jupiter are between the Earth and Io.


According to our current knowledge, Io doesn’t have any resources, that we couldn’t find elsewhere. Like Callisto, it could be used as a base to explore outer solar system, but as it does not have water, it is not an ideal place for habitats. It might be possible, that we locate some resources on Io, that are hard to get from elsewhere.


There have been some theories about terraforming of Io, but they are unfeasible with the current technology. Io has multitude of problems, that should be solved before we can attempt to terraform it.

First, we should create an atmosphere, that would also allow the greenhouse effect to raise the temperatures. Ideally, we would be able to reduce the volcanic activity, or at least choose our locations for cities carefully. We should also bring in huge amounts of hydrogen and protect it from heavy space radiation.

According to some suggestions, Io could be transported to be a moon of Venus or Mars. It would take Io away from the strong radiation belt of Jupiter, and could also probably restart the internal dynamos of the planets, allowing them to have a magnetic field. This is absolutely unfeasible with current technology, and might not ever be possible.


Io is not a very interesting target for human colonization. Its a challenging place to colonize because of its heavy volcanic activity and radiation. Also, it does not have water. There are many more interesting objects for colonization in our Solar System.

With technological advancements, having bases on Io or terraforming it could be possible. However, it is very likely that Io will be one of the last large objects that we’re trying to make habitable.