# How would you heat colonies in the outer solar system (by using natural systems)?

By Colonies 'in' the outer solar system I mean the various moons and space stations past the asteroid belt.

Currently the Hegemony has established bio domes, mining stations, and a few large scale space colonies either on the moons of the outer planets or in close proximity (as well as some Centaurs like 2060 Chiron), but heating these worlds through mechanical means (space heaters) is expensive. If they could find a way to use natural systems already in place it would save them trillions of tax payer dollars.

Now my question is: How would you heat these colonies (the moons themselves) by using or manipulating natural systems? Is there a way, for example, to somehow channel or amplify solar energy, make use of Jupiter's radiation belt, or anything else I haven't thought of?

Note: This is in the context of later terraforming the colonies (in some cases. If its impossible to terraform a certain moon you can just skip over it when answering this question) so the temperature should be at least survivable with limited equipment (arctic temperatures would be the minimum temperature).

• Really big mirror would do it but since they would have to track the sun they might end up being more expensive than heaters.
– John
Jun 14, 2018 at 14:22
• I don't know enough to make it a proper hard-science answer, but I believe properly built compost piles can be over 50 degrees centigrade. Whilst not a solution in and of themselves, I can imagine them being part of a heating system for a remote colony. Jun 14, 2018 at 14:57

Geothermal heat.

Any large body will encounter frictional heating - the descent of mass towards the core liberates kinetic energy as heat, and this heat is trapped within the body to a greater or lesser degree. This is true for any sizeable celestial body. Consider Luna:

https://www.space.com/18175-moon-temperature.html

The moon has an iron-rich core with a radius of about 205 miles (330 km). The temperature in the core is probably about 2,420 to 2,600 F (1,327 to 1,427 C). The core heats an inner layer of molten mantle, but it's not hot enough to warm the surface of the moon. Because it is smaller than the Earth, the moon's interior temperatures don't climb as high.

"It's not as hot [as Earth's interior] because the moon is smaller — hence its internal pressure is also smaller," NASA planetary scientist Renee Webber said during an online chat hosted by NASA. "The temperatures are probably lower than those of Earth

If you were on a dry and inert body like Luna you would need to install a deep reservoir with heat exchangers and then use water or some other fluid (ammonia? what is handy?) to move heat from the hot depths to the cold surface. Hot fluid comes up from the reservoir, drops off its heat in the living spaces, then circulates back down with its load of coolth.

If you were on a body like Saturn's moon Enceladus you might be able to use hot fluids naturally emerging from the depths, as we use natural hot water geothermal power on earth.

Frictional Heating Explains Plumes on Enceladus

Tidal forces acting on fault lines in the moon's icy shell cause the sides of the faults to rub back and forth against each other, producing enough heat to transform some of the ice into plumes of water vapor and ice crystals, according to a new study published in the May 17 issue of the journal Nature.

The place where this might not work is very small metallic bodies like asteroids - they are not very big and so frictional forces are small, and they conduct heat because they are metal. They might stay cold thru and thru. You would need nuclear power on these.

• Would adding greenhouse gases like methane to the atmosphere help trap this heat? Jun 10, 2018 at 15:54
• The heat is deep and already trapped - it is insulated from the surface by overlying rock / other matter. If you want to bring something you would be better off bringing uranium and using it to make heat. If you want to trap heat you have brought up from depth you should insulate your buildings and remind people they do not live in barns: shut the doors when they come and go. Jun 10, 2018 at 17:17

Nuclear Fusion! Has be done on earth, and is realistic! We couldn't yet achieve a effeciency of > 1, but we get closer, and once 1 is surpased the reaction will have been kickstarted and produce more energy than it consumes. Is it possible? Yass. Every sun does it every second of every day since suns existed and until there will be no more suns. It gives us kinda a lil bit of heat. It works like dis H2 + H2 -> 2He + a lot of energy 14 MeV or 2,2x10^-12J Sounds like not a lot but thats the result of fusion of 2 very H2 molecules

1l of H2 has 2.7×10^22 molekules.

this 1l gives us about 30 000 000 000J

30 GJ or about 8 MWh or about 1t of Coal worth of energy

Sauces:

https://www.forbes.com/sites/quora/2017/04/12/contained-nuclear-fusion-on-earth-isnt-just-possible-its-been-done-repeatedly/#c5c0d414cfd5

https://en.wikipedia.org/wiki/Nuclear_fusion

• This question asks for hard-science instead of just a creative process. Answers on these types of questions require science, you even need to provide equations, citations of academic papers or similar sources. Currently this doesn't answer the question that was asked. Jun 12, 2018 at 9:05
• Fusion is realistic as heck boi Jun 12, 2018 at 9:08
• @Secespitus done boi Jun 12, 2018 at 9:26
• @Josef This question has the hard-science tag. I don't believe that this answer fulfills the criteria for that tag. Jun 12, 2018 at 12:36
• @Josef, if you click on the hard science tag, you can take a look at the tag wiki and see the answering requirements. Please check it out. Jun 14, 2018 at 13:42