# Valuable materials in Saturn rings and comets vs. C-type asteroids

The most common type of asteroid in the inner solar system are carbonaceous (C-type), while the most common type of object in the outer solar system are comets. Carbonaceous asteroids are very rich in carbon and other technologically very valuable elements (rare metals, semiconductors). Comets are mostly made of water ice or other solidified volatiles ($$CO_2$$, $$NH_3$$). Saturn's rings are made mostly of water ice.

1. Can I assume that Saturn's rings are made of basically the same material as comets?
2. Can I assume that carbonaceous asteroids are just comets which have lost most of their volatiles? So that most comet and Saturn ring material would be just as rich in carbon, metals and semiconductors as carbonaceous asteroids, if the volatiles were evaporated.
3. I'd appreciate a table with the average elemental composition of comets and Saturn rings (I already have such a table for carbonaceous asteroids).

background

I'm a big fan of colonization of asteroids, because free space has many advantages for industry over planets. (High-quality vacuum, cryogenic temperatures, zero gravity, lots of space for big structures.) This is exactly what most high-tech instruments (like particle accelerators, superconductors, plasma chambers) need.

To build industry in free space, we need material. A lot of useful material (carbon, transition metals and semiconductors) is in asteroids in the main asteroid belt - especially carbonaceous asteroids. The problem of asteroids is that they are very far apart and a lot of time and $$\Delta v$$ is needed to go from one asteroid to another. This would limit development of large-scale civilization. Asteroids also lack volatiles like nitrogen compounds, which is a big problem for industry, life support and production of rocket fuel.

Saturn's rings seem very attractive from this perspective. They are very compact (lot of material within low time and $$\Delta v$$ requirements from each other). They are also rich in volatiles. But I'm not so sure if they are also rich enough in other materials (like carbon, metals and semiconductors) to support the full spectrum of industry and technological civilization.

• +1 for free space colonies. In the inner solar system you also have the benefit of effectively unlimited power.
– Erik
Feb 6 '15 at 14:59

According to Wikipedia, Saturn's rings are 99.9% water ice.

It also takes a lot of $$\Delta V$$ to reach. From Low Earth Orbit (LEO), trans Saturn insertion is more than 7 km/s. Earth to Saturn Hohmann trip time is around 6 years.

Another problem is lack of solar energy. at ~9.6 A.U. from the Sun, the sunlight in that neighborhood is about 1/90 as strong as sunlight here on Earth.

So at first glance, Saturn's rings are lacking as a possible location for human settlements.

Should we overcome lack of solar energy and the big $$\Delta V$$ it takes to leave Earth, I believe the gas giants' moon systems have a lot of potential. I call these mini solar systems. Many of the moons are small enough that their gravity well isn't a huge hurdle and if elevators through planet-moon Lagrange 1 and 2 regions are possible, $$\Delta V$$ is even less of a concern.

• Originaly caption of this question was "What Saturn rings are made of except watter ice?" ;-) then I changed it because I tough this more general topic would be more interesting. Feb 6 '15 at 19:47
• I'm not very concerned about distance (time, $\delta$v from Earth). I find more important the fact that civilization located in the Saturn rings would be very productive ... in the same way as United states was very productive even if it was very far from Europe motherland (or Carthage which was far from Lebanon) Feb 6 '15 at 19:53
• The Jupiter moons are also interesting. But I still prefer smaller bodies with large surface-to-volume ratio and negligible gravity for reasons I already described. Feb 6 '15 at 19:55
• Lack of solar radiation is not so much an issue. Fission nuclear energy could be comparable effective, and fussion probably more (in terms of en.wikipedia.org/wiki/Energy_returned_on_energy_invested ) Feb 6 '15 at 20:02
• Saturn is one of those things which sounds feasible once fusion power is feasible. So far from the sun, your options are geothermal, fission and fusion. Geothermal is limited to certain moons. Fission requires mining fissable isotopes. Fusion requires mining isotopes of hydrogen and helium. Hydrogen (and to a lesser extent helium) are abundant in the outer solar system and seem like the natural choice of fuel. Not saying fission wouldn't be feasible, just that there are easier places we could build fission powered colonies, while fusion would make energy abundant in the outer solar system. Feb 6 '15 at 20:07