Atomic Oxygen Detected In Martian Atmosphere (cnn.com)

An anonymous reader quotes a report from CNN: Atomic oxygen has been detected in the atmosphere of Mars, according to NASA. The atoms were discovered in the Martian mesosphere, the upper layers of the red planet's atmosphere. This discovery will enable researchers to have a better understanding of the elusive Martian atmosphere. Atomic oxygen can help scientists determine atmospheric erosion and how other gases escape Mars. It also affects the radiative cooling from the carbon-dioxide bands in the Martian thermosphere, which is above the mesosphere. The atomic oxygen discovery was made using an instrument on board the Stratospheric Observatory for Infrared Astronomy, or SOFIA. SOFIA is a Boeing 747SP jet that has been modified for research purposes to carry a 100-inch diameter telescope. Using the German Receiver for Astronomy at Terahertz Frequencies, known as GREAT, allowed researchers to distinguish between oxygen from our atmosphere and that of the Martian atmosphere. They discovered half the amount of atomic oxygen expected, most likely due to variations in the atmosphere itself, and scientists will continue to use SOFIA to study the Martian atmosphere.

Comments

SubjectsInCommentsAreStupid

[lesincompetent]

Quick! Send in the homeopathic astronauts!

Re:SubjectsInCommentsAreStupid

[Rei]

They're not available right now, they just started a 1e-24 week strike.

fp

[Anonymous Coward]

Why do people think colonizing Mars is a viable option? I ask this as a serious question. To my knowledge, the core of Mars is no longer molten. Earth's core gives rise to the magnetic field, which is essential to blocking out harmful radiation from the sun and prevents the atmosphere from being stripped. If Mars doesn't have this protection, it's going to be severely inhospitable to life and it seems like any atmosphere would inevitably be stripped. I just don't see how Mars is a viable place to live. Sure, everything could be indoors with shielding and adequate air for breathing, but at great expense of resources.

Re:fp

[ledow]

Because Venus sure as hell isn't any better (92 times the atmospheric pressure, 400 degrees hotter, sulphuric acid clouds, etc.) even if it is closer, and Mars is further from the Sun than Earth (1.5 AU instead of 1 AU).

Hence it's the nearest sensible suggestion and we have to deal with radiation on ANY long space trip anyway because there's not much like Earth's protection anywhere else. If we can't cope with the radiation on Mars, we might as well just give up now.

Re:fp

[religionofpeas]

Because Venus sure as hell isn't any better

If only there was a suitable planet between Mars and Venus....

Re:fp

[ledow]

There was.

Then we started to turn the clouds sulphuric and potentially initiated runaway greenhouse effects which started to turn it into an inhospitable barren desert with un-survivable atmospheric heat.

Or was that Venus again, I forget?

Re:fp

[religionofpeas]

If people aren't interested in fixing this planet, there's not much hope that they'll do better on Mars or Venus.

Re:fp

[Gavagai80]

From a practical standpoint, colonizing the moon makes more sense than Mars. But humans are not practical animals, and they find Mars more interesting.

Re:fp

[Rei]

Because Venus sure as hell isn't any better (92 times the atmospheric pressure, 400 degrees hotter, sulphuric acid clouds, etc.)

Venus is far better than Mars. Specifically, Venus's cloudtops - say, 54km altitude, 70 latitude (poleward might be even better, but you start facing more risk from the polar vortices, so we'll just compare 70). Earth by comparison will be equatorial, and Mars will be surface-average.

Gravity (earth relative): Earth: 1.0; Mars: 0.38; Venus: 0.9

Air pressure (atm): Earth: 1.0; Mars: 0.006; Venus: 0.5

Temperature (avg, C): Earth: 26; Mars: -30; Venus: 31

Daily variation (C): Earth: 4-30; Mars: 90; Venus: 15

Day length: Earth: 24; Mars: 24.5; Venus: 48

Ability to relocate / explore new terrain: Earth: moderate; Mars: poor; Venus: high

Overhead radiation shielding mass (meters H2O equivalent): Earth: 10,3; Mars: 0.36; Venus: 5.2

Magnetic field: Earth: 25-65uT, intrinsic; Mars: induced, 20-40nT MPR, 5-20nt magnetosheath; Venus: induced, 40-80 nT MPR, 10-40nT magnetosheath

Health hazards: Earth: those humans evolved to; Mars: 1) Fine, abrasive electrostatic dust, 2) silicosis; 3) perchlorates; 4) hexavalent chromium; 5) other chemical hazards; Venus: 1) Corrosive acid mists; 2) hydrogen fluoride; 3) probably others of relevance

Other local hazards: Earth: those humans evolved to; Mars: marsquakes, landslides, dust storms, probably others. Venus: poorly understood - lightning (although we don't know at what altitude), gusts/shear (probably Earthlike, but poorly quantified), icing (probably not, but maybe), possibly others. Needs more study, but Mars gets the lion's share of the planetary exploration budget and everything else competes for the scraps.

Delta-V to habitable area from LEO (km/s, aerocapture assumed): Earth: 0; Mars: 4.7; Venus: 4.2

Delta-V from habitable area to LEO (km/s, aerocapture assumed): Earth: 9.8; Mars: 10.0; Venus: 15.5

Transit time (months): Earth: 0; Mars: 9; Venus: 5

Launch window frequency (months): Earth: 0; Mars: 25; Venus: 19

Landing difficulty: Earth: moderate (dense atmosphere, oceans to land in, compacting soil, readily available rescue); Mars: hard (reversed conditions of Earth): Venus: easy (no landing at all; your landing ellipse is "a large chunk of the planet")

Solar energy (29% triple-junction W/m): Earth: 290; Mars: 45; sometimes almost none; Venus: 400

Capturable wind energy: Earth: moderate; Mars: effectively none; Venus: high

Diversity / value of resources: Earth: moderate (that which we're used to); Mars: probably less than Earth, but not "poor"; Venus: the planet acts as a natural refinery, baking / dissolving minerals from rocks and redepositing them in other forms; surface appears to be highly enriched in "incompatible elements" (many of which are rare and valuable on Earth) and the planet is highly enriched in deuterium.

Accessibility of resources: Earth: moderate (that which we're used to); Mars: like Earth, but hindered by mobility and the difficulty of removing overburden; Venus: mixed high/low; a large resource base is available to be drawn directly from the atmosphere and which can be distilled /decomposed by simple heating/cooling (for example, 85% H2SO4 -> H2O + O2 + SO2) - the list of known/likely elements in the clouds is very long, even involving significant iron in the form of iron chlorides). However, surface access requires heat-tolerant phase change balloons (the high atmospheric density makes "dredging" with the same fan used for maneuvering a reasonable approach)

Venus is grossly underappreciated as a destination for human settlement, and for exploration in general. Normal Earth air is its own lifting gas. Rather than living in a cramped pressure vessel, colonists would be living in an expansive, bright space perfect for cultivation. Don't like one of your coworkers? Go hang your "room" from a catenary cable on the opposite side of the habita

Re:fp

[Rei]

Note: my apologies for Slashdot eating the degree signs and exponents in the above post :P

Re:fp

[Opportunist]

It would be enough to fill those Zeppelins with oxygen/nitrogen, that mix is already lighter than the atmosphere of Venus.

Question is whether it's light enough to let heavy space ships float.

Re:fp

[Ihlosi]

You'll rarely hear about colonizing Mars from real engineers, they know it's not possible.

A real engineer will only say "not possible" if the laws of physics need to be broken. Otherwise, you'll probably get a quote. It might be completely unaffordable, though.

Re:fp

[Progman3K]

Dude, you're channelling Sagan. I love it

Re:fp

[Applehu Akbar]

Although the atmosphere of Venus above a floating station would be a much better radiation shield than the Martian atmosphere, that missing 5m of water equivalent would still present a problem, and using regolith as shielding would not be an option. Neither would bringing the 5m of water, or its shielding equivalent in something denser, along be viable, because you would then have a lead balloon. We would have to do something like generate a strong, local magnetic field.

Anyway, kudos for the detailed analysis.

Re:fp

[Rei]

I can only gather from your post that you didn't actually read mine, given that you seem to think that the conversation is about living on the surface of Venus.

Re:fp

[Applehu Akbar]

In this case, brava.

Re:fp

[Ol Olsoc]

Space nutters are ridiculous. You are going to live in the acid clouds on Venus? In 300kph winds? Christ.

They'll make pretty good time though.

Re:fp

[Applehu Akbar]

A floating platform would be a great launch and operations site for probes to the surface, which will be a highly interesting place for any device rugged enoughto survive there. You could even exercise a high degree of real-time teleoperator control from the manned platform, which we cannot do anywhere else in the solar system except for the Moon. This dramatically extends what surface probes can do there.

Re:fp

[Rei]

Wind speeds are only relevant to someone anchored to a fixed point. Venus's zonal winds are evenly moving air masses. There's still convective systems within them like on Earth, but it's anything but hundreds of kph shear.

Also, you overstate the velocity for the target altitude / latitude.

As for your "acid clouds" comment, I have to wonder if you've actually read what I've written. Incredulity is not a counterargument.

Re:fp

[Ol Olsoc]

The surface of Venus is too damned hot, so we would have to have a floating city there; bring on the mega-zeppelins!

Hydrogen would not burn in the CO2 atmosphere.

Oh man, I see a steampunk novel here.

Re:fp

[Anonymous Coward]

You forgot the main benefit of Mars which is the oxygen generators installed there by aliens millennia ago.

Re:fp

[Applehu Akbar]

Why do we have settlements in Antarctica? Why have we colonized any part of the Earth less congenial than Hawaii?

Both religion and exploration are unchangeable aspects of the human personality. They will persist despite any appeal to utilitarianism.

Re:fp

[Rei]

So you set yourself up somewhere high up. How exactly do you propose to come by non-gaseous resources?

Let's compare individual resources, shall we?

Water:

Mars: frozen in permafrost, mixed in with sand and gravel, containing perchlorates, hexavalent chromium, and other toxic chemicals. Have to build and deploy a Martian equivalent of a bobcat and scrape it out (note that mining equipment is famous for high maintenance needs). If chunks are too big they need to be run through a rock crusher. They then need to be loaded into a bin and pressure sealed, then heated, with the steam driven off creating the necessary pressure for water to be able to exist at a liquid state and flow off through filters (which will need periodic cleaning); the sand and gravel has to be emptied. The contaminated saltwater now has to either be distilled or run through reverse osmosis, the latter being unfortunately rather contaminant sensitive. It's enough of a headache that most near-future proposals just call for bringing the water (or just hydrogen to make it) from Earth.

Venus: Acidists naturally condense or absorbed (see an above post on the subject) and run straight into a boiler. There they're heated. Free water is driven off and H2SO4 decomposes, emitting more water. The steam is isolated and condensed.

The latter is much easier.

Oxygen.

Mars: There are two main proposals for oxygen production. One is electrolysis. Electrolysis systems as used on ISS have however proven to be rather finnicky, and you're dependent on the water mining above to replace any water loss in the system (which will happen over time). The other proposal is to be tested on Mars 2020: MOXIE. Martian air is drawn in and compressed, troublesome impurities removed, CO2 frozen out then reboiled at pressure, then run through a SOFC which uses a lot of electricity to turn CO2 into O2 and CO.

Venus: SO3 decomposes at elevated temperatures (much faster in the presence of a catalyst) into O2 and SO2. So the only added step here over water production is the catalyst. Separation from SO2, O2, and other elsser chemicals can be done in a specialized stage or in distillation.

Again, winner: Venus.

Let's look at starting to form an industry. So, let's look at the top 10 industrial chemicals on Earth

H2SO4: This is the number one produced chemical on Earth. Do we even need to go into how much easier it would be to get on Venus?
N2: Venus's atmosphere is denser than Mars's and N2 is about in the same percentage concentration, so the advantage is again to Venus.
C2H4: The process is roughly the same on both Venus and Mars
O2: Already covered.
Chlorine (Cl2): On Venus, this is conducted by the Deacon process (4 HCl + O2 = 2 H2O + 2 Cl2). You get free HCl from distillation and you have cheap O2. On Mars, this would be done by the much more energy-intensive electrolysis of brine. Furthermore, you'd need to either isolate out brines containing specifically chlorides first.
Ethylene Dichloride (C2H2Cl2): Used for PVC, which honestly isn't a great material for either Mars or Venus. The routes are basically the same on both Mars and Venus.
Phosphoric Acid (H3PO4): On Venus, this comes for free during distillation. On Mars... honestly, we don't really know. We've found phosphate minerals (chlorapatite and merrillite) but no concentrations of them.
Ammonia (NH3): Haber process, same on both planets.
Sodium Hydroxide (NaOH): Ah, finally something Mars can win at! Various hydroxides will be produced as a byproduct of chlorine production. As far as is known, both sodium (and similar-use potassium) can't be gotten from the atmosphere (although they're abundant in any surface rocks that may be mined for other purposes - Venus's surface-mining throughput potential being lower than that of Mars'). That said, Venus lends itself perfectly to cation recycling. Any waste (plant, human, industrial

Re:fp

[Pseudonymous Powers]

Thag: Someday, man will fly through the air, like a bird!

Grak: When, Thag?

Thag: In five years, or ten an the most!

Grak: That's impossible, Thag. You're talking like Arl after that wildebeest kicked him in the head.

Varg: Shut up, you two! You're scaring off the antelopes!

Re:fp

[Rei]

No, actually it doesn't. HAVOC has studied this, various astrobiology-potential papers have studied this, etc - I can point you to some if you'd like. The HAVOC lead author is fond of pointing out that there are places in Canada that would have a higher radiation exposure than their astronauts would be exposed to ;) A colony on Venus doesn't need added radiation shielding like one on Mars or the Moon does.

(I'm not actually much of a fan of the HAVOC proposal... but it is applicable in this case)

Re:fp

[Rei]

Dang it, I knew I overlooked something! ;)

Re: fp

[Opportunist]

Is that akin to "on the internet"? Same shit, just a different label so people think it's different?

Re:fp

[Dcnjoe60]

There was.

Then we started to turn the clouds sulphuric and potentially initiated runaway greenhouse effects which started to turn it into an inhospitable barren desert with un-survivable atmospheric heat.

Or was that Venus again, I forget?

It would be far easier to colonize the oceans on this planet than the surface of Mars.

Re:fp

[Dcnjoe60]

If people aren't interested in fixing this planet, there's not much hope that they'll do better on Mars or Venus.

The purpose of going to Mars isn't about survival of the species. Mars is far more dangerous to life than what we have caused on this planet. No, the purpose of going to Mars is to be able to exploit any resources that planet may have. Having a colony there is to get public buy-in.

Re:fp

[Rei]

You know, you could actually read the post. Something that you still clearly have not done.

Re:fp

[110010001000]

This is probably the most insightful post I've ever read on slashdot.

Re:fp

[squiggleslash]

I did read yours. I'm explaining why Venus is not likely to the target of colonists, not why your plan isn't technically feasible.

Re:fp

[Dcnjoe60]

This is all extremely interesting. Could you work up a similar pro/con for the efforts to forgo Mars or Venus and colonize the ocean shelf? It would seem to me to be more feasible. It doesn't protect from a massive meteor or comet strike, but then that possibility exists, regardless the planet. In short, I am asking, if we have messed up the surface of the planet and need to seek habitation elsewhere, would undersea be a more viable and simpler solution?

Re:fp

[Pseudonymous Powers]

You're scaring off the antelopes!

Re:fp

[avandesande]

Why don't you explain to us there merits of having your hand chopped off vs your foot?

Re:fp

[Rei]

I have trouble reconciling your post with you having read mine. You wrote:

A significant difference between Mars and Venus is that we can land someone on the former before terraforming it ... until we can deal with the fact that virtually anything we drop into it is going to dissolve within minutes, perhaps even seconds, assuming it doesn't melt first, and assuming it's not enclosed in something strong enough to prevent it from being crushed before it's melted and dissolved, it's not a planet that's going to capture any proto-colonists' imagination. .

My post has nothing to do with colonizing Venus's surface. Nothing to do with the high temperatures there. Nothing to do with the high pressures there. To a Venus colony, the surface is only secondary - for exploration and low-throughput collection of valuable / low quantity minerals. Both the living area and the main source of raw materials is the atmosphere itself.

An early to mid-stage Venus colony doesn't even need a surface probe.

Also, what you wrote is hyperbole. There are plenty of materials that tolerate Venus's environment well. Two popular ones these days are PTFE and vectran. VEGA used PTFE, although modern variants involving copolymerization with for example PPVE (Teflon NXT) or HFP (Teflon FEP) perform better in a lot of key aspects. VEGA also wasn't reinforced with a high tensile ripstop; the PTFE itself was loadbearing and the balloon superpressure, which is obviously not a scalable solution (it was more like a party balloon than a blimp ;) ).

It's quite possible to envisage us colonizing Mars before its terraformed too.

That is precisely what I was writing about, colonizing Venus before terraforming it.

If your issue is with people's mistaken perceptions about Venus what a colony on Venus would be like, that's indeed something I seek to change. People tend to think of Venus as its surface. But the habitable area is the middle cloud layer.

Re:fp

[Rei]

A 300kph wind doesn't do anything to a plane for example

You meant sarcasm, but you're precisely correct. Earth's jet streams are upwards of 400kph. Airplanes deliberately fly in them whenever possible.

As multiple people have pointed out to you, you're mixing up wind speeds relative to the surface with turbulence. Venus has high wind speeds relative to its (almost stationary) surface. It does not have high turbulence (as far as we've sampled thusfar) in it. The speed of the air mass relative to a surface over 50 kilometers below it is practically irrelevant.

I'll bet you don't think acid is an issue either

Already more than well addressed elsewhere in this thread.

It may surprise you to learn that we have plenty of chemicals that are essentially completely inert in strong acids. PTFE (Teflon), probably the most famous, is much easier to describe by what it's not inert to than what it is inert to. But the list hardly stops with it.

The real problem is not reactivity, it's permeation. But modern PTFE copolymers like NXT and FEP keep it down to reasonable levels, and liquid crystal polymers like vectran even lower.

And yes, there has been ample lab work, both in the US and Russia/USSR, including a wide range of constructed and tested balloons. And actual flown PTFE balloons on Venus (only designed for short-term operation, but enough to gather data).

Re:fp

[Rei]

The biggest factor in space travel is energy. To get to Mars you need 6.5km/s worth of evergy (E=1/2mv^2). To get to Venus, you need 12.7km/s of energy, almost twice as much). This is spent slowing down to fall towards the sun.

Slowing down lowers your orbital radius while speeding up increases it up to sqrt(2) orbital speed (at your current orbital radius) which will send you off to infinity, aka escape velocity.

The biggest factor in space travel is energy. To get to Mars you need 6.5km/s worth of evergy (E=1/2mv^2). To get to Venus, you need 12.7km/s of energy, almost twice as much).

This is incorrect. A LEO-to-Mars-intercept trajectory and LEO-to-Venus-intercept trajectory take an almost identical amount of delta-V - about 4,7km/s for Mars and 4,2km/s for Venus (the exact delta-V depends on what sort of assumptions you make, so you'll see some variation in reported figures; these are on the more pessimistic end). You're probably confusing some combination of "from the surface of Venus to LVO" delta-Vs and/or assuming capture by retroburn rather than aerocapture.

Re:fp

[thinkwaitfast]

Most scientists are against manned spaceflight.

Re:fp

[thinkwaitfast]

What exactly would a colonist 'do' on either Venus or Mars? It seems like every other day there are dozens of posts about there are no jobs on Earth and robots/AI is about to take over.

No matter where humans go outside of Earth, they would be highly dependent on automation even to the point of being irrelevant. Even on the surface (or floating in the clouds) people at most would be there to surf the internet and play video games.

What would a typical day be like? Wake up. Drink your synthetic protein/glycerin shake. Look around your 3x3m living space. Wish you were dead. Look at your monitor to see what the inside of a cloud looks like for the 3476th day in a row. Wish you were dead again. Watch the latest crappy movie from Earth just because there is nothing else to do. Wish you were dead some more. Fall asleep. Wake up on your 3477th day. Drink your shake. Wish you were dead..... It would not be any better than solitary confinement after the novelty wore off.

Re:fp

[SuricouRaven]

No-one is seriously planning to colonise mars right now. The plan is to get some humans there, have them do lots of Science Stuff, and bring them back again.

Colonisation, lunar or martian, has a serious difficulty: Cost. It would dwarf the ISS. Creating a self-sustaining colony on either body would, without doubt, be the single most expensive project in all of human history to date. Who is going to foot the bill?

Re:fp

[Rei]

There's a very long list of jobs to do on a Venus colony - some quite high tech, some that would be right at home in the pioneer days.

Early on at least, since every new bit of robotics infrastructure you want to develop comes with a sizeable price tag and even here on Earth robotic agriculture is a serious challenge, agriculture would be conducted by hand. Planting, inspections, harvesting, potentially even pollenation. Some agricultural tasks are less obvious - for example, mushroom farming, or potentially even beekeeping.

All agricultural products are in their raw state. Want to fry something? You better press your oil first. Want to make bread? You first have to thresh/winnow the grain and grind it in a flour mill. Etc. Speaking of bread, you have to keep a live yeast culture, just like was done in primitive times, because you can't just run to the store to pick up a packet of yeast.

Concerning cooking in general - feeding a whole crew, combined with the significantly increased labour of food processing, makes this a full time job. Some "cooking" tasks aren't even edible. Soap, for example, would be made just like in the "olden days" - ashes from the incinerator boiled with fat. Even paper-making (if you don't want to wipe with plant leaves/your hand/a reused brush, and don't think a bidet alone is enough, then you need this) is a kitchen task - fibrous plant matter soaked with ash hydroxides, strained in cheesecloth, blended, then pressed in a cheese press or manually spread/pressed on tensioned cheesecloth.

For a colony that wants to survive on agriculture, and where that agriculture is being conducted in a very different environment, botany / plant science is an important skillset for a crew member. Another important position is a medical staff member. Venus is too far for telemedicine, and people can't simply return to Earth for treatment. The same individual would also double as a compounding pharmacist, dentist and, when livestock raising begins veterinarian. Speaking of livestock, caring for them is no trivial chore.

All habitats will require maintenance. On Venus, you need to clean plant debris, remove any accumulated dust / grime on the envelope, make repairs as needed, and near end-of-life do major reconstruction in sections. There's ample mechanical and particularly chemical systems, to the point that you may even want a full time chemical engineer on hand, to not only maintain but also expand systems for progressively increasing local production capability. New hardware sent from earth requires installation. A small machine shop is needed for fabrication, with trained operators. Heck, even janitorial services are needed. And some chores will be less pleasant than others. The toilet, for example, would compost and/or dehydrate solid waste, but eventually you're going to have to bring it to the incinerator. Don't expect people to pay for the development and launch costs of a "robotic butler" to do all of the work for you.

Obviously researchers are going to be wanted. The more data you can gather from samples locally, the less you need to send to Earth (and the more selective you can be about what you send). On Venus, surface probes need low-latency operators; commands sent from Earth would have totally impractical round trip times when your total dive time can be no more than a couple hours. Surface probes need to be docked, unloaded, and samples hauled up to the lab and processed. The same laboratory hardware doubles as a chemistry lab for production of small batch-scale chemicals, everything from medicines to catalysts and so on down the line.

For quite some time, most effort would simply be directed toward trying to improve crew safety, sustainability / self sufficiency, and comfort. When these needs are met, however, a huge need for increased labor arises in terms of local production of new habitats. All of the huge numbers of components you already have? You need to make more of them - and bigger. No matter how much money you spend on trying to develop robotic systems to assist you, much of the construction work is still going to require humans. Quite a lot of them.

I could keep going, but I think you get the picture.

Re:fp

[Ihlosi]

Not the engineers I know. Things that require breaking the laws of physics are "problematic" or "impractical".

I'd like a quote for a time machine and a perpetual motion machine (first or second kind, their choice) then.

Re:fp

[squiggleslash]

OK, so instead of acknowledging that I wasn't trying to critique your post on technical grounds, you're digging in.

Your post was the equivalent of "The Zune is technically superior because X, Y, and Z, so people will flock to it.".

My post was the equivalent of "OK, but people like the iPod because of Q, and we can't do Q on a Zune, so it's not going to become popular."

You're now complaining that I didn't address why the Zune is technically superior. And AFTER I POINTED OUT that I never addressed which was technically superior, I was just explaining why the Zune will be ignored, instead of saying "Ah, OK, I didn't realize you weren't critiquing X, Y, and Z" you're saying "But Q has nothing to do with X, Y, and Z so you shouldn't have replied."

We're not going to Venus. We're going to Mars. We're going to Mars because we can land on it and colonize it today, without terraforming it. You might not like that, you may feel that's the wrong approach because there are technically ways in which we can float people in the clouds around Venus or half a dozen other ways, but the fact is they're not what anyone wants to do.

BTW Saturn's bigger and has the same gravity as Venus and Earth, but we're probably not going to colonize that before Mars either. For most of the same reasons (plus the radiation.)

I appreciate my posts are often opaque and I have great difficulty being understood from time to time, but I also have to say that I have little or no sympathy for people who continue to interpret a post the same way after they've been told specifically that's not what it meant.

Re:fp

[Rei]

I appreciate my posts are often opaque and I have great difficulty being understood from time to time

If you're finding this to be a recurring problem, then you might want to consider that perhaps the problem is not other people.

We're going to Mars because we can land on it and colonize it today, without terraforming it.

And the same thing applies to Venus, only even easier - plus the added convenience that you don't actually have to literally land. Once again, I'm failing to see why you keep making this statement of yours. And as long as you keep making that statement and not dealing with my reply to it, my reply is going to keep being the same. And this is going to continue to be a frustrating conversation for the both of us.

Summary of the problem you're having: saying "We're doing X, not Y because we can do X today and not Y" is a meaningless statement when we can actually do Y, and more to the point it's easier than X. If you disagree that one can do Y, you need to state reasons, rather than just being dismissive.

but the fact is they're not what anyone wants to do.

The fact is, as evidenced by this very discussion thread, very few people even know that it's a possibility. It's hard for people to prefer a choice that they don't even know exists. Bringing up a possibility that people are unaware of and educating them on the topic is not some form of tyranny, it's a perfectly reasonable course of action that you for some bizarre reason object to.

The scientific literature has been discussing colonizing the surface of Mars pretty much since spaceflight began. The first scientific paper on the colonization of Venus's cloudtops wasn't even written until 2003 (Landis).

BTW Saturn's bigger and has the same gravity as Venus and Earth,

The combination of some layer with Earth-surface gravity, air pressure, and temperature only exists in one other place in our solar system: Venus. Not Jupiter. Not Saturn. Not Uranus. Not Neptune. Not Titan. Just Earth's surface and Venus's middle cloud layer. On none of them is gravity near Earth norms at livable temperatures (it's only near Earth norms at liveable pressures on some of them), and on none of them exists the combination of livable pressures and temperature at any altitude.

And beyond all this, have you ever looked at transit times, launch windows, and delta-V requirements for Saturn? The local solar constant? How exactly do you plan to float a balloon of breathable air in hydrogen anyway? What's your local resource production tree?

Of course you don't have answers to any of these things because you weren't actually serious, you were just being dismissive of Venus - even though answers to a huge variety of topics related to a Venus colony have been discussed on this thread, and I'd be happy to discuss more. But again, you don't care about that either, you just want to be dismissive without having to substantiate your reasons.

plus the radiation

You do realize that radiation is one of the many reasons that Mars is a more difficult colonization target than Venus, right?

Re:fp

[david_thornley]

And, after whatever we do to it, Earth will be the most hospitable place in the Solar System, and it won't be close.

Re:fp

[RockDoctor]

What surprises me about the whole concept of terraforming ANYWHERE is that long, long before we have the industries and technologies to terraform anywhere, we'll have to have indefinitely-stable human habitats in space. At which point, why bother with planets?

YOU might like to feel the wind in your hair as you lay in the sunlight. If you bring them up in a habitat on an asteroid (say, delivering another petatonne of water to Mars from Saturn), they will look at you as if you are insane when you talk about exposing yourself - your skin! un-shielded !! - to thermonuclear radiation frm the Sun.

To quote Cicero (or Catallus - I forget - some dead Roman dude from 500 years into his empire), "Oh tempora, Oh mores!"

Re:fp

[Coren22]

No worries, great post.

As far as the plants, wouldn't it just be easier with those kinds of solar radiance to just use grow lights in an enclosed room? That way you can better control the day/night cycle and the color of the light, and it isn't like you are lacking for power resources on Venus.

Re:fp

[Coren22]

So, you are saying no one would want to live on the Cloud city of Bespin, but in domes on Mars (or caves which is the better solution). Personally, I think the Cloud city of Bespin is a great idea, and I would volunteer to be the computer guy on the mission. :)

Re:fp

[Coren22]

AC already gave the quote:

"problematic" or "impractical"

Re:fp

[Coren22]

Nuclear power is cheap, much cheaper than other forms of power.

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

If people would stop fighting nuclear plant construction out of a false sense of the danger, it would be even cheaper.

Fusion can be had right now in your garage, but until the funding is put into it, it will be perpetually in the future. The quote you are referring to was that fusion was 50 years out if it get $x funding, which it hasn't even gotten a tenth of over that time period.

Flying cars? They are called helicopters, you can get a license and pick one up right now if you like.

Leisure society, we are there.

Supersonic passenger transport? You mean like the Concorde, that actually ran for a number of years? If you are willing to pay, and find a couple hundred friends, it can be done, but it was found that there aren't enough people that need it, and frankly the internet replaced the need.

Yep, space better look out, since we have a settlement already there.]

If seems like you are the nutter, not the people who look at these things and talk about the actual challenges and how to solve them.

Re:fp

[Ihlosi]

A quote is a number. Of units of currency. Or "Not possible.". 'Problematic' and 'impractical' are merely terms used during the negotiation to justify the number being higher than the requestor expects.

Man is getting closer and closer

[Yanglish]

An encouraging information. Man is getting closer and closer to moving to Mars.

Re: Man is getting closer and closer

[ChunderDownunder]

Klingons circling Uranus?

Re:Man is getting closer and closer

[Anonymous Coward]

> And of course that the average atmospheric pressure is [...] around 0.5 % of Earth's seal level pressure.

To put that in perspective, the atmospheric pressure at the top of Mt. Everest is about 1/3 of that at (Earth) sea level. This is a thick, oxygen rich soup compared to Mars!

Re:Man is getting closer and closer

[Rei]

Also note that if you were to concentrate Martian air to 1ATM and simply add oxygen to reach an Earthlike O2 partial pressure, it would be highly toxic. 1% CO2 causes drowsiness, while 7-10% is lethal. Also, Mars's atmosphere is 0.0557% carbon monoxide, which while not acutely lethal is well above the toxicity limit where acute symptoms and irreversible, accumulative neurological damage occurs.

Re: Man is getting closer and closer

[Opportunist]

Stop talking about Uranus in polite company!

Ogilvy

[Hognoxious]

Ogilvy puts the chances at a million to one.

Re:Ogilvy

[mrbester]

Ogilvy was a proven idiot.

Re:Ogilvy

[Hognoxious]

The other team's medical officer wasn't much of a genius either.

Re:What is atomic oxygen?

[Anonymous Coward]

Oxygen in the periodic table of elements, like all the elements, is shown as a single atom. However, oxygen in our atmosphere likes to stick together with itself, oxygen we breathe is O2, two oxygen atoms. That's molecular oxygen. Atomic oxygen is very reactive and impossible to breathe, no matter how much Space Nutters want to believe Mars is now just like Wisconsin because someone detected five atoms there.

Re:What is atomic oxygen?

[Mr D from 63]

In simplest terms, it is single atom oxygen molecules, or O, whereas normal oxygen we think of is O2, and Ozone is O3.

Colonizing

[110010001000]

Colonizing now is easy: we just need to get the atomic oxygen to bind to each other. I will be living on Mars in 10 years, tops.

Re:Colonizing

[Coren22]

Sorry, but the mentally deficient and condescendingly pessimistic won't be invited when the colony ship is sent. So, it looks like your chances are zero of ever leaving the planet, since no one wants to be in such close proximity to you.

Re:What is atomic oxygen?

[hcs_$reboot]

I haven't been able to find a definition of "atomic oxygen". What is it? Thanks.

Try google, and click the first result link... d'oh!

Move along, nothing to see here.

[Anonymous Coward]

That's just Marvin the Martian testing the Illudium PU-36 Explosive Space Modulator

Terraform it!

[Kevin by the Beach]

1. Need an earthlike magnetic field. This would be the hard part. HUGE energy requirements, but without a magnetic field the gravity is insufficient to hold an atmosphere. (we lucked out with our built in field generator on earth)

2. Need H2O... Enough water on a planetary body with a magnetic field to retain any water vapor, along with planetary rotation and energy from the sun will start the climate cycle. The amount of water added will need to be equal to the current mass. (but, hey we almost double the gravity in the process) I would recommend dirty water (maybe 3% Organic (carbon containing) compounds)

3. Simmer for several thousand years... adjust atmosphere to taste....

Next time I run into a God like being... I'll see what they can come up with...

It's a warm, bright, sunny day by the Beach.

Re:Terraform it!

[110010001000]

1. No problem. Just bring some magnets and put them in the center of the Planet.
2. No problem. Just dig the ice up and melt it.
3. No problem. I'm sure humans will be around in several thousand years.

Signed, Space Nutter

Re:Terraform it!

[Kevin by the Beach]

LOL,

I was thinking an old 10 penny nail and some copper winding connected to a couple radio shack solar cells would be magnetic enough.

I don't think you understood my point about adding water... Digging it up wouldn't change the mass of the planet... Adding the equivalent of the current planetary mass should be just about right. (hence the reference to needing a God like being? If we could somehow borrow one of the ice moons presently orbiting our gas giants it would be a start)

Cloudy, but warm by the Beach

Re:What is atomic oxygen?

[realperseus]

http://lmgtfy.com/?q=What+is+A...

Ok, I'll bite.

[Ihlosi]

Venus is far better than Mars

Venus is interesting, but I have a hard time rating it 'better'. More specifically:

Health hazards: Earth: those humans evolved to; Mars: 1) Fine, abrasive electrostatic dust,

I would assume Martian dust isn't quite as problematic as Lunar dust is, since the former gets moved around more and hence has fewer sharp edges.

3) perchlorates; 4) hexavalent chromium;

You're not supposed to stick Martian soil in your mouth.

Landing difficulty: Earth: moderate (dense atmosphere, oceans to land in, compacting soil, readily available rescue); Mars: hard (reversed conditions of Earth): Venus: easy (no landing at all; your landing ellipse is "a large chunk of the planet")

Yes ... but fail at landing, and you'll plummet into a 450 degree C hellhole. A rough landing on Mars might kill you, a rough landing on Venus kills you before you hit the surface.

Diversity / value of resources: Earth: moderate (that which we're used to); Mars: probably less than Earth, but not "poor";

And Mars has quite a bit of water. More than Venus, probaly.

Accessibility of resources: Earth: moderate (that which we're used to); Mars: like Earth, but hindered by mobility and the difficulty of removing overburden;

Accessibility on Mars is easier, due to the lower gravity.

It's also worth mentioning that Martian regolith is expected to cause contact burns similar to lye, due to the perchlorates and other oxidizing compounds.

Exposure to Venusian atmosphere will probably eat your skin and poison you. There are also compounds of chlorine and/or phosphorous, which tend to have interesting effects on humans...

You actually could feel an alien wind on your skin, something you could never do on Mars.

You could ... short term exposure of skin to near-vaccuum should only cause reversible damage. Keep your pressure suit mostly on, though ...

In general, however, a colony on our sister planet Venus - unlike a cramped pressure vessel on Mars

Pressure vessels are only "cramped" because that's the way we build them (since most of them need to ride on rockets). I would assume that different construction technologies (inflate a large balloon, then fortify it with polymers or concrete) would allow more spacious habitats.

Re:Ok, I'll bite.

[Rei]

I would assume Martian dust isn't quite as problematic as Lunar dust is, since the former gets moved around more and hence has fewer sharp edges.

3) perchlorates; 4) hexavalent chromium;

You're not supposed to stick Martian soil in your mouth.

Martian and lunar dust have both similarities and differences. Martian dust particles are finer, athough it doesn't make them less hazardous. Despite attempts to minimize it, some exposure to the dusts will be inevitable; it's fine, ubiquitous and sticks to everything. It's well recognized as a significant hazard in mission design. One hazard of martian dust over lunar dust is that it appears to contain significant more chromium, and it's often hexavalent (a highly toxic form rarely found in nature on Earth). A number of other compounds such as arsenic appear to be of relevant risk as well.

Yes ... but fail at landing, and you'll plummet into a 450 degree C hellhole. A rough landing on Mars might kill you, a rough landing on Venus kills you before you hit the surface.

Expecting to survive a crash landing on Mars is far beyond positive thinking.

The landing processes on both planets start out roughly the same. But the processes on Venus end before the hardest parts of a Martian landing end. Once you're down to under 100m/s or so on Venus, you're ready to start with deployment**. Once you're down to ~100m/s on Mars, you still have the part that's most likely to kill you remaining.

** - Although any type of reentry system works, a ballute reentry seems particularly well-suited for Venus, as it give you an initial inflation of warm, light gases. Ballute reentry has been proposed on a number of Venus proposed Venus probes, but so few Venus probes ever get funded due to Mars' domination in the budgeting process.

And Mars has quite a bit of water. More than Venus, probaly.

Not probably - it does. But it's not in the atmosphere. It's frozen in permafrost, mixed with sand and gravel and contaminated with a good number of toxic substances. And Martian backhoes aren't exactly dime-a-dozen / low-maintenance objects.

Venus's water for a colony comes from the mists. There are two potential sources: 1) direct absorption, and 2) condensation.

1) The habitat requires propulsion no matter what. This is because in addition to the strong zonal winds that comprise the superrotation, there are weaker meridional winds that would cause a craft to drift from its desired location. While the zonal winds are too strong to overcome (nor would you want to), the meridional winds are nothing particularly challenging for an airship. An aircraft under propulsive load will have a constant stream of air moving past it - fastest directly in the propeller wash. Hence, the best way to get lots of mist along lots of surface area is to handle steering with a flexible windsock-style thrust vectoring system comprised of permeable tubing for direct absorption, and/or hydrophilic collection/drainage surfaces (see #2). Hence, the collection system is little added mass over the base propulsion system. In the case of absorption, the absorption fluid would be weak H2SO4.

The ideal situation involves large volumes of air moving at (relatively) low speeds. This means a large propeller. Hence, the ideal design for launch on a mid-sized rocket involves a propeller with two 6m folding blades stowed vertically in the center of the packed habitat during launch and cruise, rather than multiple smaller propellers stacked horizontally. A large prop is also more efficient.

2) Direct collection on the envelope. While the original Vega data was interpreted as there being no condensation/rain on the balloons, some more recent work has challenged that view, suggesting that it indicates progressively increasing mass loadings as moisture collects, then peaking as runoff rates matched collection rates. This is intere

Re:Ok, I'll bite.

[lgw]

The habitat requires propulsion no matter what.

I'm curious where your 48-hour day came from. Is there a wind band that actually moves that fast? The propulsion is to stay in the band?

The nice thing about a floating city is the lift is passive (though I guess you trade the dangers of living in a pressure vessel on Mars for living on a pressure vessel on Venus), but very fast winds seems like they'd have some very energetic turbulence, which is less good. It would be nice if the propulsion could be down for repairs without that being a crisis.

As far as water goes - you'd certainly want some way to get the sulfur out, and keep the pH no lower than Coke (which, admittedly, is lot of leeway) using materials you could also forage from the environment.

Re:Ok, I'll bite.

[Rei]

I'm curious where your 48-hour day came from.

Venus's diameter (at height) at 70 degrees/54km latitude divided by VIRTIS and VERA data on zonal winds at 70 degrees.

Winds do drop off as one approaches the poles, but not as fast as the radius of travel diminishes, so the day length shortens.

Is there a wind band that actually moves that fast?

Yes. Venus's atmosphere undergoes "superrotation", in that it rotates significantly faster than Venus's surface. It's sort of like having a planetwide jet stream (although it's not constant velocity, as mentioned previously, there are altitude/latitude differences)

The propulsion is to stay in the band?

Yes, the above is just about zonal (planet-circling) winds. There's also meridional winds (toward the poles and equator) as well as vertical flows. Propulsion is needed to overcome the meridional winds. Vertical winds - as well as changes in craft mass due to local production and buoyancy changes due to temperature, also have to be compensated for (except in superpressure balloons, but those are far too heavy for large scale operations). The two main means for this (without discharging mass and the like) is to have an ammonia-water phase change envelope located within the ballonets, against the outer wall (to avoid the risk of ammonia permeation into the living envelope). This passive stabilization system has been tested here on earth with ALICE - as the altitude drops, increasing amounts of ammonia boil off, increasing lift, while at higher altitudes it condenses out. .

The nice thing about a floating city is the lift is passive (though I guess you trade the dangers of living in a pressure vessel on Mars for living on a pressure vessel on Venus)

A note: while there is an overpressure, it's small - a couple hundred pascals. Not really much of a pressure vessel, and only a source of slow leaks in the case of a rupture. Also, it's extremely difficult to actually sink it; there's a tremendous amount of ballast (most of the craft's weight) that can be dropped - surplus water, locally produced hardware for maintenance / construction of new habitats, return-rocket propellant (the heaviest single element), and in the worst case, the return rocket itself. The habitat can be reduced to a tiny fraction of its original mass. It's also possible to create more lift via venting collected/produced breathable gases into the envelope, unbreathable gases into the ballonets, etc - as well as using propulsion for lift (during the daytime, at least)

Very, very hard to sink.

As a side note: contrary to what one might expect, the safest place (and lowest-mass configuration) for the living space is near the top of the envelope, not the bottom. From a mass perspective, it shortens the cables hanging from the top catenary curtains, which is a mass savings. From a stability perspective, you want the ballonets taking up most of the bottom. And from a simple safety reason, in the event of a severe leak, CO2 would pool at the bottom of the envelope; you don't want it smothering people.

but very fast winds seems like they'd have some very energetic turbulence

They don't. The speeds are fast relative to the surface, but that's over 50 kilometers away. Some degree of surface effects have been shown to propagate up to the cloud deck over Ishtar Terra (gravity waves), but they're weak.

You may note that Earth's jet streams are also very fast, yet they're popular for passenger jet travel. And they're far closer to the surface.

The conditions in Venus's cloud deck aren't speculative - we've actually flown there (see VEGA). Not for very long, but enough to get a general sense. The atmospheric conditions there are fairly reminiscent of flight in Earth's troposphere, with periodic storms separated by regions of calm. Als

Re:Ok, I'll bite.

[lgw]

the two main means for this (without discharging mass and the like) is to have an ammonia-water phase change envelope located within the ballonets, against the outer wall (to avoid the risk of ammonia permeation into the living envelope).

That's very cool (so to speak).

Very, very hard to sink.

Sure, but it would be a serious emergency. And patching a small tear somewhere on the main balloon doesn't sound like fun work (starting with finding it). I guess beyond a certain scale you'd be doing it from the inside, at least.

You may note that Earth's jet streams are also very fast, yet they're popular for passenger jet travel. And they're far closer to the surface.

Good point, though I was more thinking about storms. Earth certainly gets storms energetic enough to tear apart anything flying, though I have no clue how high up on Venus you have to be before that stops being a worry.

your propulsion is down all night every night

That sounds a lot safer - depending on moving parts never failing is just asking for trouble.

Are you referring to contamination from permeation, or separating the H2O and SO2 gas streams during production?

During production, but only because I hadn't thought of the other. It doesn't take must sulfur to be pretty unpleasant. But then, I'm sure we have plenty of data on how much sulfur crops can absorb before it's an issue - just hope it isn't cumulative.

Re:Ok, I'll bite.

[Rei]

Good point, though I was more thinking about storms. Earth certainly gets storms energetic enough to tear apart anything flying, though I have no clue how high up on Venus you have to be before that stops being a worry.

Storms are driven by convective potential energy, not how fast the bulk of the winds are moving relative to a surface 50km away. :) Just like how an aircraft flying within a fast-moving jet stream on Earth is usually more stable than flying lower down in the atmosphere. Most of Venus's atmosphere is, like Earth's stratosphere, dynamically stable. However, there are some layers - among them, the middle cloud layer (the habitable zone) where convective potential exists. While our experience directly flying within this layer is limited to just Vega (combined with remove observations), it appears to be roughly similar to Earth's troposphere.

If you want more specifics about Vega's measurements of turbulence: 2 balloons, 54km, 60-hour design lives (battery-powered), different parts of the planet. Vega 1's peak velocity fluctuations were about 2m/s. Vega 2's were about 1m/s. Most of the time it was significantly less. There were calm intervals and turbulent intervals. There were both small scale turbulent patches and large-scale ones. The small scale patches were about 30-130 seconds, fairly abrupt transitions, random timing. The larger ones were more periodic / slower transition, 30-90 minutes. These are interpreted as different kinds of convection cells - the small ones several hundred meters across, and the larger ones tens of kilometers across. Mariner, meanwhile, was monitoring the clouds at the balloon locations and visually spotted cloud features corresponding to the more turbulent episodes. This is extremely useful, as it gives us a way to assess the conditions in Venus's atmosphere over much longer timescales even though we no longer have any probes floating in it (that said, we definitely still need more long-term prep missions! :) ).

If you were to drop random balloon probes at the 500mb level on Earth, getting the sort of turbulence data that was received from Vega would not be at all unusual - it's neither abnormally high nor low. Nor has satellite data indicated that the Vega balloons were in some sort of abnormally calm timeperiod.

That sounds a lot safer - depending on moving parts never failing is just asking for trouble.

Nor do you use just one engine to drive the prop :) A common approach with electric aircraft motors is designs that can be chained end to end, either with a common central rotor, or linked outer rotors in the case of outrunners. Look up, for example, the EMRAX series by ENSTROJ. Each one would have its own independent inverter, and ideally the drive current would be split among multiple cables, each linked to a solar bank in a different portion of the lower portion of the craft (solar is directly printed onto the plastic, using it as a substrate; PTFE is common in usage with solar already)

During production, but only because I hadn't thought of the other. It doesn't take must sulfur to be pretty unpleasant. But then, I'm sure we have plenty of data on how much sulfur crops can absorb before it's an issue - just hope it isn't cumulative.

Permeation is one of those things which people tend to forget - I'm sure you've noticed that helium party balloons, for example, don't stay full forever ;) No plastic membrane is fully immune, although there's a wide variation. Sometimes people ask why the Vega balloons weren't fitted with solar panels - it wasn't simply about having to add solar, but also about the extra helium they'd need to compensate for leaks. Vega was from old-school PTFE, which is fairly porous (which, combined with its hydrophobic nature is why it makes breathable waterproof fabrics when expanded, ala Goretex

Very bad summary!

[Anonymous Coward]

Atomic oxygen in the martian mesosphere and upper atmosphere is old news: as said in the article it was done 40 years ago.
Mars Express and Maven observe atomic in the martian upper atmosphere oxygen daily, and with a much greater resolution than Sofia. In addition, the observation of the NO nightglow is linked to atomic oxygen in the mesosphere.
It is interesting to have a direct detection of mesospheric Martian O with Sofia (the observation with NO is indirect and therefore has uncertainties due to model dependencies, and can be done only at night, which makes problem to study the diurnal variation), but this kind of announcement is really misleading.

Re: Very bad summary!

[Rei]

One of my favorites of the more recent ones was the big hoopla over "Liquid water found flowing on the surface of Mars!" - which would have more accurately been headlined as, "Transient damp, toxic rocket propellant found flowing on the surface of Mars" ;)

I do find astrobiology quite interesting. But I've seen little to come out of most Mars astrobiology work other than overblown press releases. Tiny amounts of methane (a common volcanic gas) and the like doesn't do it for me.

Hope it is not much

[140Mandak262Jamuna]

I saw a documentary where the rockets were powered by fuel extracted from Martian atmosphere. If the atmosphere already has oxygen the fuel will all be burned off. So hope the oxygen is not much. The documentary was superfantastic, actually. They were growing potatoes in Mars!

Atomic Oxygen!

[tinkerton]

I hope it doesn't explode.

Re:Atomic Oxygen!

[avandesande]

In our atmosphere free oxygen is actually bonded to another oxygen atom and is called diatomic oxygen. Atomic oxygen is just a single atom and is more reactive than diatomic oxygen.

Re:Atomic Oxygen!

[SuricouRaven]

That it hasn't turned into diatomic oxygen suggests there isn't very much of it.