Colonization of the solar system

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Beside earth the sum of all rocky planets and dwarf planets do not provide much more surface area. Often conditions are very harsh (e.g. high radioactivity on europa). Note that there might be a lot of big transneptunian objects (TNOs) like Pluto missing in this list. Those are hard to reach though.
Planet Ceres (a dwarf planet). Located in the main asteroid belt between Mars and Jupiter it is the nearest big "waterworld" to Earth and perhaps a very attractive target for colonization. Ceres is about 1000km in diameter and the only object in the asteroid belt that is spherical due to it's own gravity. Ceres is similar in size to Saturns moon Thetys (see above image for scale). Image Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Justin Cowart


Up: Spaceflight with gem-gum-tec

This page is about how advanced atomically precise manufacturing may be usable to colonize interplanetary space. The focus is on possibilities that are relatively near term (under a century). If more far term stuff comes up this will be especially noted.

List of objects in our Solar system

Bodies with dense atmospheres are marked with a star: ★
Atmospheres can deliver building materials in the easiest processable form.
Unlike mining in rock:

  • Elements come in form of molecules that all have exactly the same "standartized" shape.
  • The material comes to you rather than you needing to come to the material.

Plus atmospheres give radiation protection and allow for aerial transport.

For more about using atmospheres as a resource

From innermost outwards

  • Mercury (planet) (the tiniest of our planets) - hard to reach because high delta-v from earth
  • Venus (12,103.6km) – is perhaps a paradise for advanced gemstone metamaterial technology.
  • Earth (12,736.5km) – Related: Seasteading
  • Mars (6,792.4km) – Thus mars is the second tiniest "normal" planet right after Mercury.
    Mars has an rather thin atmosphere (6.28mbar) that for human physiology equates to a full vacuum (pressurized spacesuit unconditionally needed).
    But it is still plenty thick enough to be usable as a building material for gemstone metamaterial technology.

Asteroid belt – advantages: big surface and area low gravity

  • Ceres (~940km) - nearest "waterworld" to Earth
  • Psyche (278±5 × 232±6 × 164±4)km – the biggest metallic planetary core remnant

Gas giants – advantage: atmosphere – disadvantage: enormous gravity and high radiation

  • ★ Jupiter, Saturn, Uranus, Neptune. See: Gas giants

Jupiter:

  • Io (~3660km) – extreme volcanic activity (mainly hot molten sulfur) and extremely radiation grilled – only the deep depths of the gas giants seem more unsurvivable
  • Europa (~3120km) – cryovolcamic activity – Skyscraper high ice spikes (penitentes) supspected – very strongly radiation grilled
  • Ganymede (~5270km) – still quite high radiation but much less than Europa
  • Callisto (~4820km) – that one might actually be a nice place for early colonization. It's the most geologically dead one of the four though due to the least tidal hating.

Saturn:

  • Titan (~5150km) – is Saturns only giant moon and the only Moon in the solar system with a notable atmosphere. It surpasses the one of Earth in terms of both density and pressure. Atmosphere blocks space radiation.

Uranus:

  • Aliel & Umbriel – both around ~1150km
  • Titania & Oberon – both around ~1550km

Neptune:


  • Transneptunian objects like Pluto and Charon

Smaller spherical moons

All smaller but still mostly spherical moons (diameters heavily rounded):

  • Jupiter: – Biggest smaller moon right after the for giant moons is Amalthea ~170km (250 × 146 × 128) – it is already far from spherical
  • Saturn #1: – Minas ~400km, Enceladus (~500km), Thethys (~1060km), Dione (~1120km), Rhea (~1530km), Titan (~5150km), Iapetus (~1470km)
  • Saturn #2: – Hyperion ~270km (360 × 266 × 205) – first moon that id quite far from round – all other ~200km and below
  • Uranus: – Miranda (~470km), Ariel (~1160km), Umbriel (~1170km), Titania (1580km), and Oberon (~1520km)
  • Neptune: – Proteus ~420km (436 × 416 × 402), Triton (~2700km), Nereid (~360km) – all other ~200km and below


Interestingly there are no objects in our solar system with liquid nitrogen oceans on the surface. Titan escapes that fate barely.
Also there are no ones with and liquid hydrogen/helium on the surface (this would need to be big objects very far out so it may be less certain).

Asteroids in the main belt between Mars and Jupiter

The main asteroid belt lies between Mars and Jupiter. Jupiter with its gravitational disturbances played a role in creating it.
There is lots of planetary core material flying around in the main asteroid belt. Shown here is a chunk of "pallasite". A material that is believed to be present in large quantities at the core mantle boundary of larger rocky planets. The green parts are olivine. An iron rich silicate.
  • pro: no gravity traps
  • pro: enormous accessible surface area - probably way greater than all the planets and moons together
  • pro: just the right temperature for the presence of a variety of materials => …
  • pro: … most unobstructed access to the perhaps the most interesting and useful group of elements
    lithophile element, chalkophile elements, and a maybe somewhat limited amount of atmophile (aka volatile) elements.

Meteoroids coming from these (and recent space missions 2020) give us info about the element distribution to expect.
See: Carbonaceous chondrites

  • con: all the material is in the solid state requiring complex mining.
    Well Ceres seems to have some subsurface briny water inside.
  • con: there is quite a bit less solar energy than on earth - but it is still enough to be useful
  • con: laggy telecommunication in a dispersed net due to light-speed run-times

M-type asteroids

These asteroids are essentially pieces of smashed up/open proto-planetrary cores.
They are giving us the only option to physically access pretty much the same material environment that is present very very deep within out earth. A material environment that will likely remain inaccessible even with advanced APM available. Check out the deep drilling page for details).

Setting up base at one of these asteroids would/will allow access to huge amounts siderophile elements (see Goldschmidt classification) These elements include Gold Au Platinum Pt and Iridium (among others) and are much more scarce on earth because they are highly depleted in our Earths crust.

Still, most interesting elements for large scale construction with advanced APM remain the most common ones.

Iron: First and foremost in M-type asteroids there is are huge amounts of iron.
This is presumably due to iron having the lowest energy per nucleon and thus being the "nuclear ash" final end product that cannot be further fusioned or fissioned any further.
(wiki-TODO: maybe add the classic energy per nucleon chart for illustration here)
And of course due to its high specific weight making it sink to protoplanetrary cores (aka the process of "differentiation").

  • Con: Iron does not form very strong gemstones with oxygen.
  • Pro: In space iron does not rust since there is no oxygen around.
  • Pro: Also as a metal with an electron gas iron may feature a bit more self healing after mild radiation hits.
  • Con: Pure metals such as iron are not optimal for APM but they can be used as long as some conditions are met which are:
  • -- (1) for preventing surface diffusion: operation at low temperatures (e.g. far out the solar system) and/or flat surfaces
  • -- (2) to prevent irreversible seamless welding: keeping nanoscale surfaces from coming too close together

Nickel: Nickel is usually mentioned as the second most common element in earths core but …
When checking out the compositions of metallic meteroids it seems that there is actually very little nickel in there and athere elements take second place.
(TODO: investigate what is going on here a bit deeper)

(TODO: list most common elements beyond iron)

The rings of Saturn

Saturns rings might remind one on a miniature version of the asteroid belt but they are completely different from a scaled down version. Both:

  • in composition – much more water ice and much less silicates in Saturns rings and
  • in distribution – Saturns rings are ridiculously thin compared to their diameter (just a few 100 meters thick – to check)

Unfortunately as of today (2021) we have no images yet of the rings from directly within the rings with such high resolution that individual ring particles are well resolved.
The end of mission choice for the Cassini space probe was to dump it into Saturn to prevent eventual organic pollution of the ring system,
instead of getting as close to the rings as possible to get ring particle pictures.

The best images we have today are:

  • Ring particles amassed on small moons that orbit within the rings. Equatorial ridges on shepherd moons.
  • Resonance structures in the rings, waves on the edges of the rings caused by these shepherd moons

See:

The few (in relative terms few) biggest pieces of ring matter are supposedly ~10m in size but most is rather gravel sand dust sized.

Interesting to think about:

  • if the rings could be mined and
  • whether that would make sense (bigger moons have much more mass and not that much gravity)
  • If human activity would influence the rings optical appearance
  • The public outcry if that actually happens ... "saturnian ring preservation society" ...

Bodies in the outer solar system

Here considered outer solar system: Jupiter beyond (Solar_System#Outer_Solar_System) all the way out to the Oorth cloud.

These are usually covered in thick sheets of structurally mostly useless ices like water ice ammonia ice or (when really far out) even methane ice and nitrogen ice. One exception to this "rule" is Jupiters innermost giant moon Io which got/gets tidally heated so much that it volcanically evaporated off all of its volatile elements despite its large distance to the sun. At least that is the naive conclusion from observations.

The only in bulk structural useful ices from volatile elements are dry-ice (CO2) an methane-ice (CH4) due to their carbon content. Titans Hydrocarbon lakes can be counted to that.

Moons and dwarf planets in the outer solar system

Furter out in the solar system small bodies become increasingly icy. Water ice and at some point even nitrogen ice becomes rock forming material. If not enough carbon and silicon is present one might want to mechanosynthesize weaker bonding ices there and use those materials for not too demanding structural purposes

Location specific flavors of gemstone metamaterial technology

Vastly differing chemical and thermal conditions at different places in the solar system could lead to differentiation (do not use "speciation"!) of diamondoid technology into very different branches.

Structures built out of water ice via cryonic inter-molecular mechanosynthesis wont find much use beside ephemeral consumables on earth since they quickly melt when uncooled or diffuse when insufficiently cooled. Further out and farther from the sun though ice and other compounds that are volatiles on earth can be seriously used as permanent building materials. This materials are also the most abundant materials in those regions so they are likely to be used.

Unlike methane water can't be safely polymerized to stuff that does not melt above 0°C. Long peroxide chains are a powerful explosives. Also oxygen polymers are un-branched linear chains and thus can't form tight meshed poly-cyclically looped covalent stiff diamondoid materials. So technology that uses only the elements oxygen and hydrogen for structural components (that is water) stays out there. Reasonably safely making explosive crystals from mostly water that do not melt will certainly be possible via mechanosynthesis since they can be made practically perfectly clean - the usefulness may be questionable.

  • Chemically reducing environments (nonoxidic compounds)
  • high temperature environments (refractory materials)
  • metal rich environments (planetary core material in the asteroid belt)

Earth remaining as the biggest place in our solar system?

Beyond Venus with only the atmosphere being moderate and the already quite a bit smaller Mars all further bodies are about Mercury sized (Titan, Callisto, Ganymede) or progressively smaller. So given looking at places like Tokyo covering large stretches of land will civilization eventually cover the smaller bodies completely with a city like surface?

Smaller bodies with lower gravity allow to build taller vertically. Albeit one will want taller floors too matching lower gravity to a point. Free space space stations of course can grow almost arbitrary large in 3D Mostly limited by desire to move them around to stabilize orbit and evade stuff on collision course. The latter even applying for space stations in stable L4 or L5 or L3-L4-L5 Lagrange point orbits.

The asteroid belt has in principle way more surface area than Earth but there the problem is communication times and travelling times. Good for gathering resources but not for living and community centers.

There are the ~1g gravity featuring outer three gas giants Saturn, Uranus, Neptune that can thus serve as a well habitable space in permanently flying structures enabled by ultra high reliability self repairing nanosystems. Same for Venus. This will need nuclear power as chemical rockets are insufficient for the gravity wells. Ideally fusion as there is an FAPP infinite supply for that in gas giants. The ice giants have more methane useful for building stuff. High scarcity of non-volatile elements may become a major issue there.

Related




External links

Wikipedia:




Spaceflight:


Sarurns pair of small-ish moons that regularly almost collide in their almost shared orbit and thereby swap out their orbits: