[krunck]

Mars has toxic levels of perchlorates in the regolith. That will require that humans never come in contact with the regolith or things that touched it. Those space suits that dock to vehicles seem like a necessity.

https://en.wikipedia.org/wiki/Perchlorate#On_Mars

[tim-tday]

Yeah, the ground on mars is literally toxic. Makes the concept of a Martian colony less appealing. Almost equal to a floating station on Venus. At least there you’d have the correct pressure. I seem to recall that the temperature on Venus at an altitude of one atmospheric pressure is manageable. It’s just also acidic. Possibility easier to deal with than perchlorates.

[LorenPechtel]

Another interesting one is Mercury. There is a latitude where the average ground temperature is comfortable for us. You simply need to dig in deep enough to put enough thermal mass above you to get that average rather than the swings. I don't know how deep that is on Mercury, on Earth 10 meters is enough. Real world, you'll want to go a bit farther towards the pole so your station is comfortable with the thermal load of whatever equipment you put in it.

[permo-w]

the swings?

[datsci_est_2015]

Assuming they mean the ground acts as a heat sink, and sufficiently underground you’re not subjected to the above average heat of the day and below average cold of the night.

[pitaj]

Isn't mercury tidally locked? Day is always day, night is always night.

[gnabgib]

It is not (it has a 88d year, and a 58.65d.. day[0]) , we just had a post about it - if you travel at 4kph you can chase the sun.. A Mercury Rover Could Explore the Planet by Sticking to the Terminator (18 points, 1 week ago, 6 comments) https://news.ycombinator.com/item?id=47720941

[0]: https://en.wikipedia.org/wiki/Mercury_(planet)

[lukan]

Without massive terraforming all of Mars is very hostile.

But having solid ground is still nice.

A workable compromise is making big habitats in a dome, that gives sunlight, but shields from radiation. And the ground needs to be processed obviously.

The advantage of Venus to me is is gravity.

[cosmic_cheese]

Gravity kind of cuts both ways. Closer to that of Earth is nearly guaranteed to be better for long term human health, but there's a possibility that martian gravity is "good enough" when supplemented with excercise while also making heavy operations and getting back out of the planet's gravity well easier.

[OisinMoran]

You may enjoy this piece, Domes are over-rated:

https://caseyhandmer.wordpress.com/2019/11/28/domes-are-very...

[lukan]

I did enjoy it, but I don't think domes are overrated. They are just way harder to build in reality, than in science fiction ..

[tarr11]

I wonder if it will turn out to be easier to adapt lifeforms to the planets than to try to adapt the planets to the lifeforms.

[lukan]

Both probably, but you cannot really adapt life to no water and hard radiation. (at most sustain it in stasis, but not growing)

[SoftTalker]

Neither is realistic; living on the Moon or Mars or any other planet is a fantasy.

[SecretDreams]

This is the thinking of someone on the timescales of a single life. If humanity persists another 1000 years on our current trajectory (US/world politics not withstanding), I think nothing is really a fantasy. Rather, it's all possible but maybe just not in our own lifetimes. But it is also terribly difficult for us to plan for tomorrow, let alone for a future where our descendants are at the helm.

[fellowmartian]

I agree, it’s just a failure of imagination. Some folks correctly foresee not being able to continue what we’re doing now in the exact same way in some new context and conclude everything is impossible. Life isn’t this fickle, it’s adapted before and will adapt again. This is why great science fiction is so valuable, as some people are better at imagining new ways of being more than others, and can show the rest of us the possibilities.

[AlecSchueler]

> If humanity persists another 1000 years on our current trajectory

It's unlikely that we can persist in our current trajectory for another 100 years without catastrophic climate events puttung a stop to all of these endeavours.

[cduzz]

Venus seems like a wonderful place to live, relatively speaking.

At the right altitude where you can "float" on the ocean, it's a pretty comfortable temperature and there's plenty of solar energy but you're shielded from the solar radiation. So, long term, your body will still work, assuming you can solve "the other problems."

Of course, the down-side is that there's nothing to stand on and probably more importantly, there aren't many useful materials to work with besides tons of carbon, oxygen, and nitrogen. Not much hydrogen there, so not much water, which probably is the biggest problem. One of them, anyhow. Also, there's probably not a whole lot to do besides float (zoom, actually) around and slowly go stir crazy in your bubble.

But relatively speaking, it's way nicer than living in a hole on mars where you'll slowly die from gravity sickness, or radiation poisoning, or whatever.

[jcranmer]

> Not much hydrogen there, so not much water, which probably is the biggest problem.

Actually, the cloud layer at that level is mostly sulfuric acid, from which you can get your water. It also means you need to be in a hazmat suit when you walk outside, but that's still a step up from everywhere else, where you need a bulky pressure suit instead.

[operatingthetan]

If we terraform mars, isn't the dirt still toxic?

[lukan]

No, as terraforming means changing that.

Whether it is really possible, is a different question, but after you have an atmosphere, you could have engineered microorganism processing the soil etc.

[marcosdumay]

Just exposing the Martian soil to water for some time is enough to destroy the perchlorates.

(Turns out there's a region in Antarctic with them too, so we can always test things there.)

[operatingthetan]

In that sense then the term "terraforming" is on equal footing with alchemy.

[wolvoleo]

Doing something like that at planetary scale is science fiction anyway even if we did have the tech to do it.

[JumpCrisscross]

> In that sense then the term "terraforming" is on equal footing with alchemy

NASA has proposed using "synthetic biology to take advantage of and improve upon natural perchlorate reducing bacteria. These terrestrial microbes are not directly suitable for off-world use, but their key genes pcrAB and cld...catalyze the reduction of perchlorates to chloride and oxygen" [1].

[1] https://www.nasa.gov/general/detoxifying-mars/

[nradov]

Which dome construction material would be transparent to sunlight but block ionizing radiation?

[LorenPechtel]

1) Why do you need sunlight?

2) If you have a source of hydrogen: water. Bonus as you don't have to make the dome hold pressure. A layer of water of the right depth will generate the force needed, the structure only needs to keep itself level. The only pressure holding is outside that, enough to keep the water from boiling. And, well, it's water--if it's hit by a rock that isn't too big you'll just have hole in the top layer, easily fixed. The same general idea would work on the Moon but the water is far from transparent if you pile up enough of it and you need a lot of hydrogen.

[lukan]

Well, I did wrote "gives sunlight" and that is a valid reply to it. But ... I would need sunlight actually. That seems somewhat possible with light tubes, but the much nicer solution, a transparent dome to still see mars clouds at day and the stars at night, is indeed not possible with current materials.

[card_zero]

Since the perchlorate is generated by reaction with sunlight, it might be limited to a surface layer.

Well, I guess that's what regolith means.

[kzrdude]

Regolith is all the loose stuff, everything that's not bedrock, even if it might be quite deep.

[vondur]

Rocket fuel for the taking?

[yieldcrv]

floating colony on venus I heard was debunked, but that was also GPT 4.1 which was misaligned so I should seek a different source, from people, when I revisit this chain of thought

[ozgung]

Sadly we underestimate the liveability of this Earth. Muskism makes people believe to the false premise that we can just buy a new planet, make it habitable with magical tech. Supported with pseudoscientific buzzwords like Terraforming etc. So we can recklessly consume this planet and jump to our new home when this one depletes. No need to care about our current home because it's a jumping board. Interesting as an old Sci-Fi fantasy so it attracts smart people, but if you really think about it's just lies and stupidity.

[api]

One of the worst things Musk did is link himself in peoples’ minds to things like space exploration and then linked these ideas to… other ideas I’m not going into on here.

All these ideas about space pre-date him by many decades.

[tim333]

Musk was also into the solar panels and EVs so it's not all trash the planet. Even if living on Mars or Venus isn't practical we might develop interesting tech trying.

[Gigachad]

Wasn’t the solar panels thing just some financial fraud scheme?

[oskarkk]

Not exactly, it was a normal solar panel business started by Elon's cousins (SolarCity), but it wasn't going well, and in the end it was bought by Tesla for much bigger money than it was worth (let's say it was a bailout for Elon). Today Tesla solar panels are maybe 0.1%-1% of the business, they stopped giving any data on it years ago.

[grosswait]

If so, they are still going https://www.tesla.com/solarpanels so I guess not

[MengerSponge]

Mars is so bad, y'all.

[chromacity]

Calcium perchlorate is only slightly toxic. Not good for you, but living in an environment with background radiation levels 50x higher than on Earth may be your bigger worry...

Still, I'm pretty sure we have plenty of people who wouldn't mind giving it a try.

[RetpolineDrama]

>but living in an environment with background radiation levels 50x higher than on Earth

We can park a big honkin magnet at the mars-sun lagrange point and cut that down massively.

[amluto]

On the one hand, it's not particularly toxic as toxic things go. On the other hand, 0.6% is not a small concentration.

[burnt-resistor]

Anyone venturing to Mars is likely taking a one-way trip for many reasons.

[LorenPechtel]

Personally, I suspect all anoxic environments will turn out to be unhealthy for humans. You'll have a bunch of reactive stuff about that on Earth would have been neutralized long ago.

[mr_toad]

> That will require that humans never come in contact with the regolith or things that touched it.

It’s really only a concern if you ingest it.

[chmod775]

Not a big deal then either. Just don't do it daily.

[imglorp]

Or effective decontamination performed in the airlock. There was a recent demonstration of an electrostatic repulsion device reducing dust on suit fabric which might help with sticking. And an air shower like used for clean rooms does not seem too far out.

[nomel]

Is that required?

Could the suit itself be used as a type of airlock, to leave outside things outside?

For example, mounting yourself onto a wall, then the back/whatever of the suit opens to the inside, and you hop out? (yes, there would be some dust recovery required, but minimal in comparison)

[imglorp]

The challenge with the "suits stay outside" model is that you basically need some kind of airlock between the suit hatch and the ship hatch. You might imagine both hatches get contaminated when the suit is detached. Then when you dock, that whole between-hatch space needs to be decontaminated before you can open the two hatches, because the outside of the suit hatch brought that stuff into the airlock.

Someone else linked to this: https://en.wikipedia.org/wiki/Space_Exploration_Vehicle#Spec...

edit: in that context^ search for "SEV suitport design" find NASA has written some docs on the matter, eg https://ntrs.nasa.gov/api/citations/20130013652/downloads/20...

[nomel]

It looks like that requires a panel to move out of the way. I was thinking more like "zipper" (probably more of a contiguous interface), so closer to zero volume when attaching, then it "unzips"/splits and pulls the back of the suit open, into the cabin.

    |
    |     /\ 
    | to |  |  
    |     \/

I don't see why an intermediate airlock would be required, except maybe for redundancy/safety reasons if the "unzip" process went wrong.

Since the inside of the suit is already at pressure, you could just pop it open and step out.

The near-zero volume of the coupling would make things much easier to clean/isolate.

[JumpCrisscross]

> mounting yourself onto a wall, then the back/whatever of the suit opens to the inside, and you hop out?

Isn't there a plan for the Artemis lunar rover to be configured this way? The outside of the suit never comes inside the rover.

[fulafel]

I'm not a Mars colonisation advocate, but sounds like exposure to that may be manageable:

"Perchlorate is toxic to people only in the sense that it can disrupt the production of thyroid hormone, an important growth hormone needed by babies in the womb for normal development." (from https://www.scientificamerican.com/article/perchlorate-life-...)

Lots of people have this condition without perchlorate after all and it's just simple meds to fix it.

[darknavi]

If this fact piques your interest, the book Delta-v by Daniel Suarez glances off this fact and uses it to justify exploring asteroid mining instead of a colony on Mars.

[LorenPechtel]

I'm not impressed with his science.

[bertylicious]

I'm not impressed with your comment.

[jancsika]

If we redefine our community to include tardigrades the outlook improves considerably.

Example: a blog critiquing Mars colonization pointed out that humans cannot even live at the summit of Everest, and there is no "non-native microbial life" there. Notice the caveat: "non-native?" Guess who else did:

Tardigrade in Hawaiian shirt, wearing pixelated sunglasses

Honestly, which achievement would be considered more impressive-- Neil Armstrong setting foot on the Moon, or me getting there first because I was stuck to the bottom of his boot?

Well, guess who is now watching you navigate to the Wikipedia tardigrade article[1]:

Tardigrade lowers its pixelated glasses

Hell, in the five minutes that I've imagined them joining the team we've gone from

"never come into contact with the regolith"

to

"if you happen to come into contact with the regolith, remember: stop, drop, and roll."[2]

1: Ok, a tardigrade was probably not on his boot for the first Moon walk. But suppose we gently placed some the surface of the Moon, and observed their reaction...

two tardigrades pointing at you navigating back to Wikipedia

2: https://sciworthy.com/could-tardigrades-survive-on-mars/

[ck2]

there's a great PBS Space Time for that (of course)

https://www.youtube.com/watch?v=O5FqozA4IpA

[charlieyu1]

Can we decompose the perchlorates for oxygen and energy?

[snthpy]

TIL