
Saturn's largest moon may be the only place beyond Earth where humans could live - mastry
https://blogs.scientificamerican.com/guest-blog/lets-colonize-titan/
======
keiferski
Two thoughts on this topic:

1\. The film _Gattaca_ (1997), in addition to being an excellent, inspiring
film all around, centers on an aspiring astronaut's upcoming trip to Titan.
Highly recommended.

\-
[https://www.youtube.com/watch?v=lZa83dTf4JA](https://www.youtube.com/watch?v=lZa83dTf4JA)

2\. The colonization of Venus is also a fascinating idea that isn't talked
about much in comparison to the Moon or Mars. Essentially, the surface is too
hot for colonization, but it may be possible to build floating cities ±31
miles above the surface.

\- _Venus 's atmosphere is made mostly out of carbon dioxide. Because nitrogen
and oxygen are lighter than carbon-dioxide, breathable-air-filled balloons
will float at a height of about 50 km (31 mi). At this height, the temperature
is a manageable 75 °C (348 K; 167 °F); or 27 °C (300 K; 81 °F) if we could get
5 km (3.1 mi) higher_

\- _The atmosphere also provides the various elements required for human life
and agriculture: carbon, hydrogen, oxygen, nitrogen, and sulfur._

\- _Additionally, the upper atmosphere could provide protection from harmful
solar radiation comparable to the protection provided by Earth 's atmosphere.
The Atmosphere of Mars, as well as the Moon provide little such protection._

[https://en.wikipedia.org/wiki/Colonization_of_Venus](https://en.wikipedia.org/wiki/Colonization_of_Venus)

~~~
aaron695
> floating cities

We have decided on Mars, can we stop forking it. Have we learning nothing from
Linux?

But if you have to, could you hurry up and make a floating city on earth to
_practice_?

People would pay a tonne of money for that, and having floating cities (In
reality small communal groups, so more a village) would be very very neat.

~~~
rbanffy
> make a floating city on earth to practice?

Earth's atmosphere is lighter than the Venusian one at that altitude. A
balloon filled with breathable air would float naturally. You can't do that on
Earth.

~~~
LargoLasskhyfv
According to
[https://en.wikipedia.org/wiki/Cloud_Nine_%28tensegrity_spher...](https://en.wikipedia.org/wiki/Cloud_Nine_%28tensegrity_sphere%29)
you can.

~~~
rbanffy
It is possible. Just don't expect living space to be bigger than a hot air
balloon basket for the size of a reasonable hot air balloon.

------
Ajedi32
Everyone in the comments here debating the merits of Mars vs the Moon vs Titan
seems to have missed the whole point of this article. The author is arguing
that anywhere _other_ than Titan is infeasible due to recent research
suggesting that Galactic Cosmic Rays cause significant brain damage (not just
increased risk of cancer). In fact, the article argues that the danger is so
severe that even getting to Titan quickly enough to mitigate the risk of brain
damage during the trip will be a major challenge.

If true, this complicates things significantly. Does anyone know if the
dangers of Galactic Cosmic Rays are really as significant as the author is
claiming? The author references the 2016 paper "Cosmic radiation exposure and
persistent cognitive dysfunction"[1] which was a study conducted on mice. Has
there been any further research into the possible effects of cosmic radiation
exposure on humans?

[1]:
[https://www.nature.com/articles/srep34774](https://www.nature.com/articles/srep34774)

~~~
FiatLuxDave
Here (below) is one of the referenced papers from that article, which
basically asserts that the worst case long-term scenario (solar minimum) would
give about the same amount of dose that the mice had in the study in about two
years in space. Of course, a solar event would give a lot more dose quickly,
but that is the kind of thing one can have a shelter for.

[https://academic.oup.com/rpd/article/115/1-4/44/1600988](https://academic.oup.com/rpd/article/115/1-4/44/1600988)

The interesting thing to me is that the dose to the mice in the study was so
low, and still had measurable neurological effects. 30 cGy is not nothing, but
in humans 30 cGy is about what a radiation worker might receive in 6 years at
the legal limit, and is about 11 times lower than the lowest estimates for
LD50/60 in humans (the amount of radiation which will kill 50% of the exposed
population within 60 days). I don't normally work with mice, so I had to look
up some info on them. Apparently the LD50/30 for mice varies a bit depending
on strain, but it is in the range of 7 to 8 Gy. That is not that incredibly
different from humans, because humans can have a similar LD50 if proper care
is given.

Sources:

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743168/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743168/)

[https://dental.nyu.edu/content/dam/nyudental/documents/Irrad...](https://dental.nyu.edu/content/dam/nyudental/documents/Irradiator_Protocol_Radiation_Exposure_of_Mice.pdf)

I don't know if the reason for the neurological effects at such low doses are
because of the heavy ions used (which would be bad for space travel) or if it
is because of the way it was measured in mice (not my field, I can't speak to
that). But I note that airline pilots regularly receive career doses a bit
lower to what the mice did (30 cGy ~= 300 mSv). And this dose is directly from
cosmic rays, the same thing we are worrying about here.

Bringing us back to Sci Am: [https://www.scientificamerican.com/article/air-
travel-expose...](https://www.scientificamerican.com/article/air-travel-
exposes-you-to-radiation-how-much-health-risk-comes-with-it/)

~~~
godelski
I'd like to add some nuance to this discussion. It is important to note that
accumulative dosages is very different from short duration dosages as well as
that 300mSv whole body dosage for a human is drastically different than 300mSv
whole body dosage for a mouse.

Also, according to the paper 50mSv showed no affect to cognitive performance.
The paper notes that Brookhaven National Laboratory can supply dose rates
between 5 and 25 cGy/min, so these dosages were given over very short
timeframes. This matters.

So we have somewhere between 5mSv (over ~1 minute) having no effect and 30mSv
(over 1-2mins) having a statistically significant decline in cognitive
performance (they did measure activated microglia in 5mSv but note that Oxygen
had a different effect than Titanium). So we can clearly see that mice, in the
worst case, are recovering after 24 weeks. This means the body can repair
itself. This is why it is important to talk about the timeframe that a dosage
was received.

So as to the 20mSv that most European countries use as total yearly dosages 1)
this is well below a statistically significant measure in cognitive decline 2)
this dosage is over a year and not over a minute (also likely weighted to
extremities, like hands, as opposed to total body). So comparing this to
radiation worker dosages is not a great comparison.

As to space flight, there are actually a lot of new rad (pun intended)
technologies being developed (I worked on some of these). The primary concern
in solar radiation is from charged particles (mostly protons, then alpha).
These are relatively easy to block (in comparison). A lot of concern now is
currently with neutrons and high energy particles. Current technologies are
frequently a big chunk of titanium, kevlar, and spectra/dyneema (UHMWPE).
Plastics are rather good as neutron shields because of their hydrogen density.
Many of these are now being doped (boron is a common one, anyone pushing
gadolinium hasn't run simulations for the energy levels we are concerned
about. Or plastics doped with metals, like titanium, to increase their
effectiveness against charged particles). This is a big optimization problem
where layer size and order are important variables. Dopants can become charged
and reradiate, but this can also be beneficial. Incoming radiation energy also
DRASTICALLY changes the equation, as higher energy particles "ignore" a lot of
material (see snide comment about gadolinium and thermal neutrons). It is a
complicated and challenging problem for anyone interested, but importantly, we
are making major improvements.

P.S. if we were REALLY concerned, you can just surround your spaceship with a
large body of water. Problem is that this is heavy and extremely expensive to
transport in space. The problem isn't really about _can we block radiation?_
but _can we __cost /mass effectively__ block radiation?_

------
beefman
The dangers of radiation on Mars are greatly exaggerated. The dangers of low
gravity on Titan and elsewhere are greatly understated, as is the immense
distance between Mars and Titan.

A floating habitat on Venus is harder and less attractive in every way than a
rotating space station, which is clearly our next milestone in space. In terms
of planets though, there's a reason Mars gets the most attention: it's
obviously the best choice.

~~~
rootbear
I, too, have concerns about how well humans will thrive in low gravity (the
moon, Mars, etc). Over time, we could evolve a branch of humanity, "Homo
ares", for Mars, but it won't be easy. Venus is just a tragic waste of a
planet. So close to Earth in size, so wrong in every other way.

~~~
wmeredith
> Over time, we could evolve a branch of humanity, "Homo ares"

These were called Belters (as in asteroid belt) in the excellent book series
The Expanse, which is also an excellent sci-fi show available on Amazon.

~~~
ghaff
The Expanse is quite good. But the earth/Mars/Belt differences are mostly
cultural at least in the TV series. The "Belters" meme in SF has been around
for a long time though. See Larry Niven for example. (And I'm sure it's older
than that.)

~~~
JdeBP
Jeff Prucher's _Brave new words_ gives its earliest attestation for the word
as Niven's _Warriors_ in 1966.

~~~
ghaff
I would have guessed Heinlein but I don't see evidence he used that particular
term although he had similar tropes in his books--e.g. Loonies in The Moon is
a Harsh Mistress.

~~~
JdeBP
For similar tropes, see the meteor miners in E.E. Smith's _Grey Lensman_.

------
baron816
The whole idea of colonizing other parts of the solar system just seems like a
fool’s errand to me. Colonizing Antarctica or even the bottom of the oceans
seems like a _more_ practical endeavor to me.

As uninhabitable as Antarctica is, just think about the advantages it has over
a place like Mars or Titan: a breathable Earth pressure atmosphere, 1G
gravity, abundant water, not outrageously extreme temperatures, low radiation
levels, close to civilization, etc.

Probably most importantly, you don’t have to escape Earth’s gravitational pull
to get there. In fact, you can use one of humankind’s earliest inventions—a
boat.

If we were really afraid of an extinction level event such as a nuclear war or
extreme climate change, humanity could survive by doing the same sorts of
things here that we would have to do on Mars—building large underground
habitats. _Except_ , we could survive in much larger numbers since it would be
so so so much cheaper to build those habitats here.

~~~
njarboe
People don't dream of traveling to other planets to create a backup
civilization for Earth. That is what those people tell the ones who don't
understand their dream and why they should support it. People want to explore
because a certain segment of the population would love the adventure, danger,
excitement, thrill, and exotic experience. One also has the chance of creating
new places outside of existing governance structures. A group of people who
start building a city on Antarctica would likely be kicked off by force in a
short period of time. On Mars, who knows?

~~~
abdullahkhalids
"We began as wanderers, and we are wanderers still. We have lingered long
enough on the shores of the cosmic ocean. We are ready at last to set sail for
the stars." Carl Sagan

------
cookingrobot
Let’s colonize Mercury. It’s not actually hot at the poles - it’s shaded
enough from the consistent low angle to the sun that there’s even water ice.
And the planet is full of useful metals (more than earth), and as much solar
energy as you can handle. The article dismisses Mercury out of hand as “too
hot” but I think it’s our best bet. [https://www.universetoday.com/130109/how-
do-we-colonize-merc...](https://www.universetoday.com/130109/how-do-we-
colonize-mercury/)

~~~
Nimelrian
Getting stuff to mercury is hard though. IIRC it takes around 16,000 m/s of dV
to get from LEO to the surface of mercury. Titan would take even more (19,000)
but a huge chunk of it can be reduced by making use of aerobraking.

~~~
Tuna-Fish
Going to mercury on rockets alone is a non-starter, because when you drop your
perihelion low enough to rendezvous with it, your velocity near Mercury will
be ridiculous, and there is not enough atmosphere at Mercury to shed the
velocity so you have to do it the hard way.

However, there is a very efficient trajectory that could be used by solar
sailing ships for a fast, cheap route to Mercury once every 16 months. You
leave Earth for Venus, where you do a gravity assist to drop your perihelion
significantly below the orbit of Mercury, just to get low enough that a
reasonable solar sail can get reasonable thrust even with significant cargo.
Then you can use your infinite delta-v to match your aphelion with Mercury,
and can do an efficient capture trajectory.

~~~
cattlemansgold
Is there an estimate for how long that would take with a solar sail? If the
window is every 16 months and the flight time is another year or more, I would
imagine a large scale mission with multiple re-supply trips would be pretty
difficult.

------
tekkk
Hmm. I have always considered low-gravity to be quite a big issue for any
planetary colonization. Unless some cure is invented like a genetic mutation,
it would seem that there is no way of coming back to Earth after spending a
lifetime in eg 0.2 G.

This in mind I have always thought that Venus would make the best candidate in
the solar system. With 0.9 G it would be as close as we could possible get to
Earth yet however I have to admit, having no magnetosphere would be a giant
pain in the ass. But since Venus already has a thick atmosphere, it would seem
that after the required amount of gas has been removed, it would stay stable
whereas in Mars you'd constantly have to offset the escaping gas. Possibly
though that would not be an issue, since we are pretty great at the green-
house gas generation.

But yeah, Mars would definitely be the easiest to terraform. But you wouldn't
come back to Earth from there. And you'd mostly spend your life in bunkers
underground to avoid getting beamed to death by the solar wind, same as with
Venus. Unless we some day find a way to achieve immunity against it.

~~~
Dumblydorr
Mars is definitely the easiest place to colonize, by far. It's much closer
than the gas giants, there's no craft capable of taking people to Saturn even
devised, let alone constructed. Meanwhile, we have SpaceX actively building a
rocket for Martian colonization.

Second, the Venusian atmosphere is oppressive as hell, you'll not be solving
that problem anytime soon, as we can't even solve Earth's much easier
atmospheric GHG problem.

Martian colonization will be tough. 30% gravity, 3% atmospheric pressure,
radiation, very cold, very dry... however, building a base is conceivable and
we think we know how to do it.

~~~
rbanffy
> SpaceX actively building a rocket for Martian colonization.

It's unknown whether it is capable of protecting the human cargo on its way to
Mars. Maybe a design with habitation encased in the propellant tanks is a
better idea for longer transits.

In any case, Starship is well positioned for Earth and Moon travels, as well
as for sending equipment to LEO and the Moon.

~~~
btkramer9
Worst case radiation they'll receive is comparable to if they've been smoking
cigarettes the whole trip. That's pretty damn good if you ask me

------
Symmetry
I'd tend to Jupiter's outer big moon, Callisto, as a good place to live. The
surface is a vacuum, sure, but it's got surface ice which probably has liquid
water underneath making it (and Ganymede and Europa for the same reason, and
Venus 50 km up, and Earth) one of the few places in the solar system you could
theoretically go outside with just a breather and no space suit. Plus it's got
protection from charged particles via Jupiter's magnetic field without
suffering from Jupiter's own radiation. And you've got both volatiles _and_
minerals accessible on the surface which strikes me as really nice.

~~~
_sbrk
All these worlds are yours, except Europa. Attempt no landing there.

~~~
Symmetry
Fine, the surface is very radioactive (but it's safe under the ice) and there
aren't any exposed mineral deposits so you can have it. :)

------
WalterBright
Colonize the moon first:

1\. plenty of solar power

2\. close to earth

3\. easy to launch out of its gravity well

4\. lunar base technology can be iterated far more rapidly

~~~
JoeAltmaier
Colonize the top of Mt Everest first? Even closer to Earth. Similar
challenged. 250,000 miles closer to resupply. Very hard, a good test of
colonizing technology.

~~~
saiya-jin
Won't develop space travel and sustainment technologies much. With that logic,
we can colonize oceans (and probably discover a thing or two about our origins
and new life forms)

~~~
JoeAltmaier
Why not? The top of Mt Everest is remarkably similar to Mars surface, for
instance. I'd say, tackle the challenges a few at a time, instead of jumping
in the deep end!

To go further: if you can't establish a colony on the top of Mt Everest, you
haven't a prayer of doing it on Mars where there are all the problems and
more.

~~~
chr1
We can establish a colony on top of Mt Everest, it's just not useful or
exciting enough to spend money and time on it. Mars is exciting and allows to
start a new country, unlike Everest which already belongs to someone.

~~~
JoeAltmaier
Still I assert: if you can't colonize Mt Everest, you sure as hell can't
colonize Mars.

------
muzani
> It’s cold on Titan, at -180°C (-291°F), but thanks to its thick atmosphere,
> residents wouldn’t need pressure suits—just warm clothing and respirators.

I'm no space colony expert but am I missing something here? -180°C sounds like
constant space suit level, not "just warm clothing".

~~~
bregma
A generous slathering of bear fat or whale blubber is all it would take. Maybe
a vinyl outer suit so the viscious liquid methane rain doesn't dissolve your
insulation.

On second thought, some kind of heated space suit sounds more comfortable.

~~~
muzani
Something like butter freezes at -20 C. Most animal fats would probably...
shatter at the temperatures of Titan? I'm not familiar with temperatures
anywhere near that low and I assume a lot of materials are just going to act
very differently.

------
yardie
If you can you should check out the TV series Avenue 5. It’s a sci-fi comedy
and whoever they hired to do their science is really knocking it out the park.
Some of the true science I’ve seen in the shown: the ship is massive enough to
have its own gravity. Objects that get lost in space don’t float away. They
orbit the ship. They use passenger effluent as a cosmic radiation shield. And
due to an anomaly they don’t get flung off into space. Their orbit gets wider
so instead of a year trip it’s now 5.

Oh and the real engineers work in the basement of the ship. The bridge crew
are actors.

~~~
carapace
I gotta disagree. The physics in the show is disappointingly cartoonish in my
opinion. The ship is not massive enough for it's gravity to capture the, uh,
various items in the orbit shown. Even the orbital mechanics of the delay are
just a plot device.

~~~
stevenwoo
The latest episode has people freezing solid after leaving through an airlock
almost instantaneously- someone on earth survived a longer exposure to vacuum
but at closer to room temperature in a suit failure.

~~~
carapace
(ノ°Д°）ノ︵ ┻━┻ Thanks for the heads up.

(Space is cold but it's also empty. You'd boil first from the lack of pressure
then freeze, eh?)

~~~
carapace
Oh gawd, it's even worse than that: they don't even leave the airlock, they
lit. freeze solid the very instant the outer doors open (with no rush of
air!?!) Damn it. I really really like Hugh Laurie (one of the great and simple
pleasures in life is introducing someone who only knows him from "House, M.D."
to his OG work like "Black Adder" or "Jeeves & Wooster") but it's hard to
watch around the problems in this show.

Like it's fucking _dark_. The bad physics wasn't the worst part of that scene.
The show is supposed to be a comedy but that was like a nightmare.

------
mannykannot
Am I missing something here?

"On the surface, vast quantities of hydrocarbons in solid and liquid form lie
_ready to be used for energy._ Although the atmosphere lacks oxygen, water ice
just below the surface could be used to provide oxygen for breathing and _to
combust hydrocarbons as fuel._ " [my emphasis.]

They are proposing splitting water to get oxygen for burning hydrocarbons to
produce energy - but splitting water itself takes a lot of energy, and low-
entropy energy at that. Could this process possibly result in a net increase
in useful energy?

~~~
m4rtink
Even if it does not, you could use it as a nice chemical battery.

Say you split some water ice using energy from you nuclear reactor (or
possibly even a turbine in your methanoelectric dam!) and store the
pressurized oxygen.

Then you can use the stored oxygen with methane from the atmosphere to provide
a lot of energy where needed, possibly far away from your main nuclear
reactor, dam on a liquid methane river or other non-portable energy sources.

~~~
Bedon292
An example would be rocket fuel to leave, so you don't have to bring it all
with you.

~~~
m4rtink
Definitely, can use it to power chemical rockets as well. :)

------
state_less
Let's colonize LEO. You get radiation protection from earth's magnetosphere.
You get zero G for funsies. You get a new perspective on earth and interesting
new kinds of manufacturing. It's not too far away, so you can get there and
back in a day. It's far enough in space that you need to improve your closed
cycle systems. You might survive a number of different cataclysms. It seems
like a good stepping stone.

~~~
garmaine
> You get radiation protection from earth's magnetosphere.

Only in very specific orbits (NOT the ones we are currently using, btw.) The
Earth's magnetosphere actually captures dangerous radiation and various
anomalies in the belt distribution cause portions of low-Earth orbits to be
irradiated.

> You get zero G for funsies.

And the medical issues.

> interesting new kinds of manufacturing.

There are a handful of (very interesting) crystal manufacturing that requires
zero-g. These could be done in automated or human tended LEO or LLO
manufacturing labs. You don't need a large human presence.

To the downsides, LEO lacks any resources whatsoever, and still has a
nontrivial delta-v to the rest of the system. All your arguments in favor
could be applied to the Moon, which does have LOTS of resources and better
radiation shielding.

~~~
state_less
I'm not trying to take the wind out of the sails of any vehicles going
elsewhere, just think LEO is a good place to start. Something like, before
crossing an ocean, let's cross the Florida straits over to the Bahamas.

> The Earth's magnetosphere actually captures dangerous radiation and various
> anomalies in the belt distribution cause portions of low-Earth orbits to be
> irradiated.

Pick the favorable orbits. We have data on our ISS astronauts. Seems like we
can go years up there if we wanted.

> And the medical issues.

Most folks are going to want to go up for a few weeks/months and then come
back to tell the tale. A habitat might employ centripetal acceleration.
Anyhow, I think medical issues will be manageable. I suspect there are a few
orders of magnitude more people who are interested in a vacation in space or
work from space scenario than a long distance voyage to the moon or mars where
you are cut off from the home world and have a big latency cost on
communications.

I think this is about filling rockets with large sums of cargo to keep the
space business growing. If a starship can be made for $5 million, there are
plenty of yachts just down the coast from Cape Canaveral that cost more than
that. If you could give folks a stay in LEO for ~$50k, there will be plenty of
people who can afford that. I bet you could find tech companies that would let
you work remotely from space as a signing bonus.

> There are a handful of (very interesting) crystal manufacturing that
> requires zero-g. These could be done in automated or human tended LEO or LLO
> manufacturing labs. You don't need a large human presence.

Agreed, I'd add that this isn't so much about keeping the number of people
down, but increasing the demand for people to go into space. I'm excited about
the side effects it will have for technology and science.

> To the downsides, LEO lacks any resources whatsoever, and still has a
> nontrivial delta-v to the rest of the system. All your arguments in favor
> could be applied to the Moon, which does have LOTS of resources and better
> radiation shielding.

The moon and mars are good places to settle too. I'm only arguing that Earth
LEO is easier to start with because Earth has more readily available resources
than any of the other locations. LEO is still hard enough where we'll have to
improve our ships and space quarters for design and comfort. So I think it's a
good stepping stone.

~~~
mjevans
LEO is more like 'camping in the back yard'.

All I ever learned from that is that I hate camping... and would much rather
have a house / hotel room.

Extending that analogy further, maybe we can figure out how to build a "mother
in law apartment" in our "back yard" first.

------
Tepix
The article argues that on Mars we'd have to live underground which requires a
lot of construction of tunnels and excavation. It does not appear to take into
consideration the huge lava tubes that are present on Mars (and even bigger on
the Moon). These are estimated to be dozens of kilometers long and hundreds of
meters wide. They could be very attractive for human colonies.

On the other hand on Triton, even if you live at the surface, the Sun will be
very weak. The main advantage of not living underground will be less resources
to create a habitat.

I consider sufficient natural sunlight to be important for human wellbeing.

~~~
DarthGhandi
Shielding Mars is possible with current technology.

[https://phys.org/news/2017-03-nasa-magnetic-shield-mars-
atmo...](https://phys.org/news/2017-03-nasa-magnetic-shield-mars-
atmosphere.html)

~~~
dylan604
Is it though? The link only discusses the theory of placing a large magnet in
the Mars-Sun L1 point. It does not discuss the makings of that magnet. What's
going to power it? Solar? Nuclear? So at the end of the day, I'm still left
not knowing if we have the tech to be able to do this. This seems like a no-
brainer of something should/needs/must be done to make humans living on Mars
anything more than just a though exerciser.

~~~
DarthGhandi
At it's simplest is a ring with power flowing through it, the power
requirements would be minimal, 1 Tesla needed and a deflection of a fraction
of a degree.

I've seen estimates in the single digit MW range which we build solar plants
on Earth for a few million each. Power generation is somewhat irrelevant,
getting the material up there and maintaining it will be the real monetary
challenge.

Read the link at the end of the popsci article. There's a huge amount of
research going into generating magnetic fields for spaceships and inhabited
bases.

------
davedx
Not a single comment calling out this article's complete lack of scientific
references, including the "iron smashing our brains at relativistic
velocities" quote?

I think it's great to consider other planets we can colonize, and indeed a
thick atmosphere has a lot of benefits, but it's hardly rational to state Mars
has "a deal-breaking problem" without providing any hard evidence to back up
this claim.

~~~
mustntmumble
Scientific American is a magazine for the general public that have a high
school level education in science. It is not a peer reviewed scientific
journal, thus the SA articles do not have the same level of footnotes and
references that a scholarly journal might. Having said that, I think on
balance, the quality of journalism in SA is excellent, thanks in part to
highly skilled and qualified editors.

Anyway, this article by the "discoverer of the Solar Wind" (maybe validator is
a better word), Eugene Parker, is relevant to this discussion:
[https://www.dartmouth.edu/~sshepherd/research/Shielding/docs...](https://www.dartmouth.edu/~sshepherd/research/Shielding/docs/Parker_06.pdf)

------
solarengineer
This reminds me of Wanderers, by Erik Wernquist.
[https://vimeo.com/108650530](https://vimeo.com/108650530)

There's a scene at the end when one of our future generation looks at the
surface of Saturn while standing on a station floating atop a Saturnian moon.

Very motivational.

Other videos by Erik Wernquist are motivational too: New Horizons:
[https://vimeo.com/132183032](https://vimeo.com/132183032)

~~~
LargoLasskhyfv
While the technical quality of these videos is very good, and i really, really
like most Sci-Fi, why in hell is she wearing a fur collar on her hoodie over a
full face mask, in space?

THAT are things things turning me off, from full hard-on to instantly shrunken
balls.

Try this, this is where we are:
[https://www.youtube.com/watch?v=KCJzUiBZItk](https://www.youtube.com/watch?v=KCJzUiBZItk)

------
siffland
Serious question, since this is out of my swim lane. The Author keeps talking
about the effects of Galactic Cosmic Rays, do we have any usable materials we
can build habitats out of that can block them? I mean usable in the sense we
can produce in scale and they are non toxic to humans.

~~~
Balgair
For Cosmic Rays the only thing is just a lot of atomic nuclei. You need pure
mass. This is why a transit to Mars or Saturn is going to be hard for us to
pull off in the near term. All those nuclei are expensive to get into orbit
right now.

Outside of that, there is a 'graded Z' shield. Here, you make a layer cake of
various atomic nuclei (the Zs), going from heavier to lighter. Typically
Tantalum down to Tin and down to Aluminum. They physics here aren't super
important, but for lower energy radiation, you can get down to a 60% mass
reduction for similar shielding protection.

The problem is that it's the higher energy radiation that you are worried
about, the Cosmic Rays. Graded Z shields pretty much work like anything else
at those energies. Under our current physics mumbo-jumbo, you just need
nuclei.

~~~
Miraste
Artificial magnetic fields are another possible solution.

~~~
Balgair
Yeah, for the less energetic stuff. The same issue applies, the very energetic
stuff just sails right on in. Big EM fields also don't deflect neutrally
charged stuff like Cosmic Rays and neutrons. Radiation shielding is hard stuff
and it'll take multiple methods working in tandem.

------
Santosh83
Let's first _ensure_ we do all possible things as a species and a collection
of communities to restabilise Earth and give ourselves a 99.5% chance of
healthful survival for the next 200 years, which is probably the reasonable
timeline until we can establish more or less independent non-Earth habitats
that can survive without Earth indefinitely.

This is like expressing the wish of wanting to run while simultaneously
ignoring the fact that your hands are uncontrollably stabbing your legs with
safety pins.

~~~
austincheney
Why not do both?

~~~
pyrale
Mainly because right now, any significant endeavour is tied to using massive
amounts of fossil fuel.

As long as it will be the case, we won't be able to start new, large scale
projects without jeopardizing our ability to live on earth.

~~~
keiferski
> Mainly because right now, any significant endeavour is tied to using massive
> amounts of fossil fuel.

But does that actually matter in space? I am asking out of genuine curiosity
here: does using fossil fuels in space have any real downside? There is no
atmosphere, ergo no greenhouse effect. The vastness of space would seem to
swallow up any sort of pollution.

~~~
muzani
That's... a different question. Where would you find fossils on other planets?
The article says Titan has seas of hydrocarbon, but otherwise Moon and Mars,
it's just not an option. One reason why Musk has invested so much in non-
fossil fuel tech is not so much to save this planet but to operate things on
other planets.

~~~
keiferski
Sure, but my broad question was essentially: are there any negatives to using
"dirty" forms of energy like nuclear, coal, or oil in space?

~~~
garmaine
> are there any negatives to using "dirty" forms of energy like nuclear, coal,
> or oil

One of those is not like the others.

Nuclear is the cleanest form of energy we have, cleaner than even wind or
solar power.

~~~
keiferski
[https://en.wikipedia.org/wiki/Radioactive_waste](https://en.wikipedia.org/wiki/Radioactive_waste)

~~~
garmaine
If I were snarky I’d reply with the wiki link to industrial waste. Here’s an
article with details:

[https://www.forbes.com/sites/michaelshellenberger/2018/05/23...](https://www.forbes.com/sites/michaelshellenberger/2018/05/23/if-
solar-panels-are-so-clean-why-do-they-produce-so-much-toxic-waste/)

~~~
keiferski
You are already being snarky and this conversation is not very useful. I was
simply asking if there are any downsides to using energy sources (that give
off dangerous waste products) in space.

I didn't mention anything about solar being dirtier than nuclear, nor did I
ask for some kind of debate on the topic.

------
lurquer
Let's start with a self-sustainable colony at the South Pole. Or, for that
matter, a self-sustainable colony in Death Valley.

"But even if we could, why would anyone want to?" you might ask...

And that's the point.

Nobody would want to as there is no economic reason to be there.

My two cents: we'll never colonize a moon or planet. There are, on the other
hand, some economic perks to manufacturing in zero-g. Consequently, I'd put my
money in massive orbiting space stations.

------
fnord77
terraform venus. it's much closer, has a nice .9g and maybe a viable long-term
project

[https://en.wikipedia.org/wiki/Terraforming_of_Venus](https://en.wikipedia.org/wiki/Terraforming_of_Venus)

~~~
austincheney
It is theorized that Venus once had an Earth like atmosphere. Venus has
virtually no magnetic field unlike Earth. Without the protection of something
like the Van Allen radiation belt the Sun would have easily blown off any thin
high density atmosphere and eventually cook off any surface level hydrocarbons
into a thick hazy atmosphere with a super greenhouse effect. Any terraforming
effort would have to take that into account and capture atmospheric sulfur.

~~~
AdmiralGinge
I suppose any attempt at terraforming has to create oceans if we want an
Earth-like habitat (theoretically this could be achieved by re-directing
enough comets at Venus or Mars provided we can utilise that kind of energy in
the future). Could perhaps a form of sulphur-fixing bacteria be developed to
colonise these oceans and remove it from the atmosphere as sediment?

As for the magnetic field, if the lack of convection in the core is a problem
(perhaps due to the core completely solidifying) couldn't we just dump enough
heat energy into it to restart the dynamo action? In the future it's not
completely unrealistic to think antimatter production and storage will
improve, that's certainly a way of releasing absurd amounts of energy.

------
RangerScience
Sincere question: Anyone know what would be involved in igniting Jupiter, and
what kind of heating that would provide to it's moons?

~~~
csunbird
Throw in more mass, than it will ignite itself and be the second sun.

Actually, when you think about it, Jupiter is a good candidate for a dyson
sphere.

~~~
robotresearcher
Jupiter is around 1/79 the mass of a red dwarf. So it’s only 1/79 better than
empty space as a place to build your new star.

------
SEJeff
There has been a few people I've read about proposing a solution to this on
Mars. Mars is absolutely chock full of these "lava tubes" caused by old long
dormant volcanos. If those could be sealed, they could be used for humans to
live in effectively shielded from this sort of thing. Sure it would be
difficult, but so would everything on mars. The great thing is that there are
lots of these lava tubes that could potentially be inhabited.

[https://phys.org/news/2017-09-lava-tubes-hidden-sites-
future...](https://phys.org/news/2017-09-lava-tubes-hidden-sites-future.html)

[https://www.inverse.com/article/36777-mars-moon-human-
colony...](https://www.inverse.com/article/36777-mars-moon-human-colony-lava-
tubes)

------
mentos
What’s more likely in the next 5000 years that we colonize Mars or that we
scan the human brain and move it to software so that it doesn’t need a
specialized atmosphere to persist?

~~~
chr1
That's a very interesting question. I would guess that if moving brain into
software is at all possible, there will be very little reason to build
anything other than huge computers, and maybe that's the answer to Fermi
paradox.

------
novalis78
I am pretty sure the Martian congressional republic is not going to stop
colonizing just Mars. They’ll have every incentive to push further, faster :-)

------
shawkinaw
> The weak gravity—similar to the Moon’s—combined with the thick atmosphere
> would allow individuals to aviate with wings on their backs.

Sign me up.

------
bayesian_horse
Both Mars and Titan currently lack an economical reason to try and live there.

As long as it's just about the science or bragging rights, it will be
completely paid for from earth's resources, instead of building on its own.

Any idea what tangible "export products" could make a Mars colony sustainable?
I don't think space tourism is enough.

~~~
mjevans
Re: Economics

'The belt' would best be mined by automated, semi-remote controlled machines.

The Moon offers a good target to fire those resources at (aim to roughly keep
it's orbital momentum the same), a low but not No G fab area with easy access
to 'free' vacuum, and is usefully close to Earth orbits.

Mars... I can't really think of any particular thing it does better offhand,
that couldn't instead...

Lagrange Points (L4 and L5) offer areas usefully distant from Earth for
scientific and world-ending-event backup purposes, have a relatively low
escape velocity, and are "safer" in that they draw masses to stay near them.
This would be a great place to park a large rock (for shielding) and core out
the inside.

[https://en.wikipedia.org/wiki/Lagrangian_point](https://en.wikipedia.org/wiki/Lagrangian_point)

~~~
kyuudou
Reminds me of what they did with the space station in Seveneves!

------
bayesian_horse
Technically, much of the spaces needed for food production or other industries
on mars don't need to be underground to protect Humans from radiation. Plants
and machines can tolerate it much better, and a Mars colony can't sustain
itself without levels of automation that look ridiculous to our present day.

------
jerome-jh
Why not colonize deserts on earth? It is vastly less energy consuming, vastly
more useful, but no less of a challenge.

~~~
kingkawn
Because if you’re talking about things we can’t do anyway might as well talk
about the ones that we can’t do the most

------
viach
Maybe consider Earth's oceans first? It's somewhat closer, has some food
resources, the gravity is also OK.

------
rmason
I thought Elon Musk wanted to terraform the poles of Mars to make it more
habitable. He even has promised t-shirts that say Nuke Mars.

[https://www.space.com/elon-musk-nuke-mars-
terraforming.html](https://www.space.com/elon-musk-nuke-mars-
terraforming.html)

------
needs
It looks a better bet to colonize Mars with genetically modified humans to
sustain radiation. If such technology is not available at the time, having DNA
correcting machines to give birth to sane humans is probably going to be a
solved problem by then. Even though adults will suffers from the radiations.

------
jaspergilley
This article projects too linearly to the future: terraforming Mars, for
instance, would probably be easier right now than getting people to Titan
quickly. Seems like an article written for the purpose of getting clicks by
being contrarian, not seriously investigating the science

------
LargoLasskhyfv
OMG! It's full of fumes! All the times!

That is all i could think about when reading about the hydrocarbons. Imagine
having to live in the all permeating STINK of a gas station, or worse
(petro)chemical factory.

/me shudders

------
wiz21c
Nitpicking, but ... If one says :

>> We reached this conclusion after looking at the planets in a new way:
ecologically

then, why can he say :

>> Housing could be made of plastic produced from the unlimited resources
harvested

Ecology is also about realizing that resources are limited.

------
blackrock
I think it’s a better idea to just build a rotating space habitat.

Harvest the metals from the moon, and build a mass driver to launch it into
Earth orbit, where it’ll get assembled into the space habitat. Then spin it to
get 1g.

------
mothsonasloth
How does this Methane develop on Titan vs. other hydrocarbons (Ethane,
Propane) etc. ?

Could we not bomb Titan with some sort of water catalyser and burn up a large
amount of Methane?

Certainly would be good as a fuel source.

------
rice_otaku
We gotta do it before the Hive and Fallen colonize it.

------
gridlockd
Let's first figure out astro-mining and self-sufficient space stations.
Planets or moons are overrated as habitats.

------
JoeAltmaier
Is it impractical to protect space colonizes with powerful superconducting
magnets to deflect harmful radiation?

------
Vysero
It all seems like a huge waste of resources and effort to me. Personally, I
would rather see all that money/resources going into developing some kind of
FTLT. There are planets out there, way out there, which are much more suitable
for life. Even without FTLT even if it takes us 2 generations to get there.

------
davidhyde
It’s “Scientific” American yet they quote negative 300 degrees Fahrenheit. Use
kelvin for low temperatures or, if you have to, at least degrees Celsius. For
the benefit of the reader -300 F is 89 kelvin or -184 Celsius which is about
10 degrees c above liquid nitrogen’s boiling point.

~~~
tantalor
The article is about human colonization, so Fahrenheit is more appropriate
unit because it represents human compatible temperature ranges better than C
or K.

~~~
3solarmasses
Exactly. Very few people get this. Fahrenheit is better for communicating
temperatures in daily life.

Plus we can be more precise in our language due to the expanded scale. e.g. We
can say 62 degrees F, rather than 16.6667 degrees C.

~~~
shawabawa3
> Exactly. Very few people get this. Fahrenheit is better for communicating
> temperatures in daily life.

Literally the entire rest of the world disagrees with you

I've never needed a less than 1 degree unit for describing temperature, except
in scientific contexts, where using 2 decimal places is fine

I don't see why "100 ~= body temperature (with fever)" is a useful scale
point. Or why 32F = freezing is useful in daily life

~~~
athenot
Normal body temperature was defined† in Celsius, at 37ºC; this explains the
decimal when used in Fahrenheit (98.6F). So even that argument of convenience
doesn't hold.

† Yes everyone's baseline temperature is slightly different, but that just
makes the decimal on the Fahrenheit scale look even sillier. And fever
definitions are also keyed off of Celsius: 37º to 38º is "low grade". Sure,
it's an arbitrary convention but it's the one adopted around the world,
including in the US (98.6 to 100.4).

~~~
shawabawa3
Whether it's off by a degree or 2 doesn't matter (as you said body temperature
varies)

But why is 100 ~= body temperature more useful than 100 = boiling water?

Why is 50 being kind of cold more useful than 10?

I don't get this "Fahrenheit numbers are more
useful/convenient/understandable" argument

~~~
tantalor
As a human person, temperature relative to my body is more useful than the
boiling point of water at ~100 kpa.

Anyways, in Titan's atmosphere water boils at ~110 C, so much for "100 =
boiling water".

------
hristov
Great idea. We should use Titan to build a bunch of insane asylums there. And
then perhaps we can neglect the insane asylums, the patients can escape and
start their own societies based on the type of disease they have.

------
b34r
Someone read the Kurt Vonnegut book, The Sirens of Titan!

------
hwestiii
The Dr.Manhattan Project?

------
0-_-0
The page is "temporarily unavailable" for me.

To help in your fight against paywalled and temporarilty unavailable pages,
here's this (officially recommended) Firefox extension that looks up the
current page in one of 18 web archives:

[https://github.com/dessant/web-archives](https://github.com/dessant/web-
archives)

------
blueboo
Let's. But first, let's colonize the ocean. And the sky. And the moon.

------
mistrial9
It is deeply disturbing to see a lot of effort put into colonizing another
planet, while rampant pollution increases at Planet Earth. While science
advances, at what opportunity cost?

It Remains to be Seen if we have Spoiled the Nest. <\--

------
mnm1
What exactly is the problem that colonizing another planet or moon is trying
to solve? This seems like a solution without a problem. And if that problem is
that the earth becomes uninhabitable, what kind of moron thinks we can
colonize a planet or moon when we can't even keep ourselves alive on earth?

~~~
otabdeveloper4
"We trashed this planet, let's find another one".

------
marcusKral
As a doctrine, colonization hasn't worked too well for humanity. It assumes an
ethnocentric view where the colonizer has the right to take or use resources
that they believe they "discovered". Just because there aren't any humans
there, doesn't mean it doesn't already belong to someone. And just because we
are able to take over a moon, doesn't mean we have the right to.

Instead of colonizing, we should be talking about zero impact exploration
where we leave things exactly as they were before we arrived. Then focus on
using what we learn to fix and protect our own planet.

~~~
shadowprofile77
Belong to who? All known solar space and beyond is literally devoid of any
life at all. Are you assuming super aliens? Or perhaps a god of some kind, who
pre-claims ownership? And if so, how did these beings get their "right" to
have it?.

What exactly countermands our right to the take over the moon or any other
part of local space? Name some concrete thing, not just an arbitrary notion of
rights.

The obvious from these, to what purpose zero impact exploration of space?
Sure, nothing should be destroyed just because... But you do realize that
you're not talking about fragile ecosystems here, but vast dead landscapes
that are the literal products of cataclysmic destructive processes that are in
many places still ongoing?

Your comment is so absurdly out of context for the environments we're all
discussing here that it's tempting to think you're trolling.

~~~
marcusKral
And that's exactly the problem... we don't know what we don't know. We are
assuming life exists only in the form that we have encountered it on Earth.
And we're assuming that just because we can't find something, that it isn't
there. We are taking all things solely from our perspective and we are
convinced that they can't be any other way. This seems extremely egocentric
and could be disastrous when encounter something far outside of our narrow
perspective.

And what if we find a bacteria on Titan that lives beneath the surface but is
harmful to humans, will we exterminate it for our own sake? What level of
intelligence is required before we attribute value to another species.

As far as rights are concerned, this is a real issue. If the first country to
Titan plants a flag and then says, "This moon is ours". Does that make it
theirs? Will countries fight wars to protect their perceived rights to a
particular moon? It may be arbitrary but that doesn't mean it isn't real.
National boarders are arbitrary but they are very real. But in the same case
as with countries, what gives us the right as a species to go a moon and claim
it. Is it a right based on force, an ethical right, a right of first claim?
The very idea of colonization assumes certain rights. The question is what are
those rights based on?

And no I'm not trolling. It's sad that we are prepared to discuss ideas
without being prepared to discuss the underlying philosophies. I'm simply
saying that before we consider what to colonize or how, we should consider
whether the very notion of space colonization is valid. This isn't a moot
point. If we're wrong, at worst it could mean the end of our species. All
cases of colonization on earth have lead to genocide or war... no exceptions.
Why do we think space colonization will be different?

