Floating Venusian cities or Venus vs Mars vs Titan revisited

RobertDyck · 2007-06-10 16:19:08

The object which collided with protoEarth did not become the Moon. That was engulfed by Earth itself. Luna is our crust flung into orbit. The composition of Luna is basaltic lava rock -- 100% of Luna matches the "sea floor" rock of Earth ... which means the cratons pre-date the collision.

Ok, that's way more detail than I was aware of. One of the things I love about the Mars Society is you meet so many informed individuals. I'm always learning.

Thanks

nickname · 2007-06-10 16:23:23

Spatula,

Could be just the sulphur has gobbled up all the free oxygen.
Sulphur dioxide.

If Venus has had volcanic activity for most of its life then the quantity of sulphur should be a good candidate to gobble it up.
It sounds like a decent creation theory for Venus, so its probably wrong LOL

I still like the idea of a few titanic head on collisions causing the thick atmosphere and tilt/spin of Venus and much less water than Earth at the start.
No need for oceans of water and a very problematic explanation of how we get them to disappear with collisions.
Direct collisions explain most of what we see on Venus, but its always nice to see its possible to create a Venus a few ways.

StarDreamer · 2007-06-10 16:28:16

I doubt this. Terrestrial rocky planets tend not to grow coeval moons, while the gas giants do with some uniformity. Mars has only 2 tiny captured asteroids. Mercury and Venus have nothing. Then Earth has this whopping big moon -- clearly an extraordinary situation demanding an extraordinary explanation.
Earth's hill sphere extends 1500 thousand km from the planet's center. That's a lot of room for a moon. Ours is only in the first 25% of it. Mars and Venus only have moderately smaller regions to form moons. There's no reason Venus couldn't hold an impact-formed moon, so your argument that it never had one would have to rely on finding a simpler, more likely explanation for its current rotational velocity.

That's not what I wrote. I said "terrestrial rocky planets tend not to grow coeval moons". Coeval is the big word here -- meaning a moon which accretes out of the planet's disk, both independent of the planet and yet in the same "egg sack" as the planet -- from the same yolk. Not by capture or by collision, but by accretion -- that is coeval. Luna is not coeval with the Earth. Earth had already formed and its disk was fully condensed or collapsed into a sphere, likely a smaller sphere than Venus is. Then Earth got walloped by another protoplanet the size of Mars and the layer of light elements on its surface got peeled away with such force that it was lifted beyond the Roche Limit and was able to form a new body. The continents, like Africa (which is very elevated overall), represent the thickness of the crust before impact. If you calculate the cubic volume of Earth's oceans, I think it approximates the cubic volume of the Moon -- but I can't remember if that is to sea level, to the continental shelves or to the average elevation of the continents.

I agree that there is no reason Venus could not hold an impact formed moon, but such a moon is born out of very special circumstances in an impact. What I am saying is that there appears to be some conditions in the stellar disk which work against formation of planetary satellites in the inner system. It may be just "material deprivation" in the womb.

Spatula · 2007-06-10 21:52:12

Spatula,
Could be just the sulphur has gobbled up all the free oxygen.
Sulphur dioxide.
If Venus has had volcanic activity for most of its life then the quantity of sulphur should be a good candidate to gobble it up.
It sounds like a decent creation theory for Venus, so its probably wrong LOL

Still not nearly enough SO2 to account for oceans worth of water. Which is good, because if the Sulfur Iodine cycle really were responsible for eating Venus's oceans, Earth would look like Venus too. We have exactly the same process here, due to Earth's volcanic history. Alternatively, oxygen could be on the surface as FeO2, as it is on Earth and Mars, or in other mineral forms. It probably is, but still can't store nearly enough oxygen to make a dent in Earth's oceans.

We're talking about enough water to make a very respectable sized moon.

I agree that there is no reason Venus could not hold an impact formed moon, but such a moon is born out of very special circumstances in an impact. What I am saying is that there appears to be some conditions in the stellar disk which work against formation of planetary satellites in the inner system. It may be just "material deprivation" in the womb.

What special circumstances? 11% of TNOs are in multiple-body systems. That ratio goes up a lot the larger they get. This region of the solar system is a lot like the early solar system, but frozen in time. These objects were far enough away from each other and the Sun to remain in the same region without coalescing. In the inner solar system, large collisions and moon formations should be similarly common, but most of them wouldn't be stable over geological periods.

Perfectly fitting for this case. Though, as Nickname said, the destroyed moon isn't the only explanation for Venus's rotation or surface composition.

nickname · 2007-06-11 05:19:15

Spatula,

Yeah it's pretty tough to match up free oxygen exactly with sulphur as a contributor if we try to match the quantity of c02 from h20.
Even adding other possible oxygen gobblers we should still have quite a bit of free oxygen left.

A pretty good reason exists why Venus wouldn't have anywhere near as much water to begin with anyway.

In the early solar system as you pointed out the sun was about 25% hotter,
Most of the water/ice comets that could make it to earth at this period could not make it to Venus as ice balls.
Only the very big ones would have made it all the way to Venus, loosing most of the mass on the way.
The smaller ones just don't make it at all.

Even in todays cooler solar system comets start out gassing long before the earth orbital area.

Just working on that one point we could expect maybe 25% or less of the water earth has to make it to Venus.

This also works well to calculate the water content of Mars, mars gets 1/4 of Earths water quantity because it's 1/4 the mass of Earth and moon.
A hot Mars with little magnetic field and weak gravity looses most of its water until it freezes the remaining, free oxygen is turned into iron oxide and peroxide on the surface.

Venus is never a cool place due to lost retrograde moons and head on collisions, its water deliveries are turned into steam and contribute to the c02 content of the atmosphere.
At 25% of earth water quantity the h20 matches the carbon counts and we get no free oxygen, the continual release of sulphur gobbles up any excess oxygen.
The high c02 quantity of Venus we see today is caused mainly from combining 3 or 4 atmospheres from different bodies Venus has collided with and extreme volcanic activity when these events occurred.

Earth is 25% hotter but retains most of it's water because of its magnetic field strong gravity and temperatures below boiling water.
When we get the first pools of water to form on the surface life takes over to start eating up co2.

Works for all 3 places.

Spatula · 2007-06-11 12:57:24

Pretty reasonable. I would put 10-15% Earth's water as the potential upper limit Venus could've had, with something around 1-2% as the most likely amount. Now it wouldn't even be comparable. 1.86 mBar, pretty pitiful.

nickname · 2007-06-11 18:03:32

Spatula,

Thanks

Just wish we had an orbiter going around Venus doing a incoming h20 count.

If that number came in much lower than the current Earth totals we could put the boiling oceans theory of Venus to bed.

My guess would be about 10% of the water earth got Venus got.
5% or less isn't out of the probable though.
If we guess that 95% of Earth water delivery was from small comets and ice balls then the total arriving at Venus might be quite trivial with the sun that hot.
Especially when even the big ice balls will loose 1/2 the original mass in getting to Venus.

1.86 mb, what does that work out globally 1/4 inch of water?

RobertDyck · 2007-06-12 00:24:12

You don't know how much minieral sulphur is on the surface. SO2 consumes a lot of oxygen. Furthermore, solar wind deposits some hydrogen and deuterium. Actually more hydrogen departs Venus than deuterium, so the deuterium:hydrogen ratio is increased by solar wind. Furthermore solar wind is the exhaust from a nuclear fusion reactor, a lot of it's hydrogen will be converted to deuterium by the fusion reaction. All this makes the deuterium:hydrogen ratio meaningless. Add to that the fact that starting with the same water as Earth would have resulted in total water loss hundreds of millions of years ago and you have a meaningless argument.

The bottom line is Venus is 94.886% the diameter of Earth, 90.0% surface area, and surface gravity that is also 90.7%. It's so close to Earth dimensions that you can expect similar starting conditions. The only difference is the lack of a large impactor, and lack of a large moon. It's proximity to the sun will affect whether a liquid water ocean forms, but not how much water it had to start with.

StarDreamer · 2007-06-12 02:37:03

I am wondering if Venus without its atmosphere might resemble Jupiter's Io -- lots of sulphur and vulcanism.

nickname · 2007-06-12 05:33:05

Robert,

I'm not so sure Venus would start with similar water totals.
Even with todays cooler sun if we started the planet forming process again Venus would still receive much less than 1/2 the water earth does.
Simple mass loss of water/ice objects at Venus orbit vs Earth orbit.
Little icy objects even in todays solar system that make up most of the water earth receives don't make it to Venus.

With a warmer sun the mechanics of getting water to Venus becomes more difficult.

That first billion years or so when most of the cometary objects were crashing on the planets is also when the sun was hotter.

Another problem with Venus starting with vast ocean quantities of water is that the proximity of Venus to the sun allows oceans to form.

If we account for all the water becoming co2 at Venus and it had similar totals to earth then the start bar pressure before the boiling oceans is around 8 - 10 bars with 3 of them being nitrogen.

Even if we pretend that those 5 - 7 bars are the worst possible co2 and sulphur content and the sun is 25% hotter we still get oceans to form.
Once we have oceans on Venus it's very difficult to start them boiling.
Especially difficult with large quantities of sulphur and water vapor helping to create very reflective thick clouds.

The chemistry of boiled oceans works well to explain the Venus 92 bars co2 atmosphere of today, but not well in getting that chemistry to start.
With such thick clouds we don't get the needed UV in the majority of the cloud bank, we end up with most of the water vapor being in a protected zone.

With a cloud filled Venus we still get water to separate and hydrogen loss but not in quantities the boiled ocean theory would have to explain.
Lots of other reasons why i think the boiled ocean theory isn't that solid.

Mineral sulphur on the surface of Venus would tell us two things, when the water content of Venus was lost and how active Venus has been volcanic.

That would be very useful information.

RobertDyck · 2007-06-12 14:40:04

I reviewed the known data on Venus and found hydrogen chloride and hydrogen fluoride. This is interesting because of what those compounds will do under temperature and pressure.
SO2 + 4 HF -> SF4 + 2 H2O
SF4 + 2 HF -> SF6 + 2 H2

Hydrogen chloride will create a side reaction, but the monochloride is, however, a strong oxidant and readily hydrolyzed to sulfate.
SF4 + HCl + HF -> SF5Cl + H2
SF5Cl + 2 O2 + H2O -> SO4 + HCl + OH

Other sulphur fluorides will form, such as S2F10, but they "disproportionate" by heating, breaking down into compounds with a single sulphur atom. For example:
S2F10 -> SF6 + SF4

Forming sulphur hexafluoride requires high temperatures and pressures in an anoxic environment, but that's exactly what Venus atmosphere is. SF6 is a strong greenhouse gas, 22,200 times that of CO2, so even trace amounts would have a powerful impact on Venus. SF6 is a heavy gas so would tend to sink, and free oxygen in the cloud layer would tend to disrupt it's formation. Is there SF6 on Venus? Is this one reason it's so hot?

Another issue is calcium. On Earth we had high pressures and high CO2 atmosphere similar to Venus, but once a liquid ocean formed that CO2 dissolved into the ocean where it combined with dissolved calcium to form calcium carbonate. That formed limestone inorganically, sequestering much of proto-Earth's CO2 atmosphere. Is there insufficient calcium on Venus to do that? I suspect there is sufficient calcium in Venus surface rock, it is a light metal. Or did it's proximity to the sun never let it cool to form liquid oceans in the first place? That's more likely. Fluorite (aka fluorspar) is a common fluorine mineral on Earth: CaF2. It forms in low temperature vein deposits. Cryolite (Na3AlF6) also forms in cool areas on Earth. Is Venus just too hot to sequester fluorine?

StarDreamer · 2007-06-12 14:51:25

So once again Venus has in abundance what Mars desperately needs ...

Very good research!

nickname · 2007-06-13 06:00:57

Robert,

Interesting, sulphur hexafluoride would get Venus to the mad greenhouse with a much better result than just co2 from h20 and sulphur does.

Can we get sulphur hexafluoride to form below the boil point of water on the early Venus?
Lets say maybe 10 bars of pressure and 50c at the surface, maybe in the intense UV zone it's not to difficult.
If Venus is a volcanic nightmare at this time with mass quantity of free sulphur that also helps.

That could explain why 10 bars of early atmosphere got set above the boil point of water, then all the water deliveries were just turned to steam.
We need a lot less water arriving though for it to work because the free oxygen will interrupt the process if it gets to high.
How do we get from 10 to 92 bars pressure though with much less water?

We should still see small amounts of sulphur hexafluoride in the atmosphere of today.

RobertDyck · 2007-06-13 08:12:39

I got a lot of my information from Wikipedia:
http://en.wikipedia.org/wiki/Sulphur_hexafluoride

Actually there's another interesting piece of data here. I read one paper that talked about using electrical explosions of platinum metal to decompose SF6, resulting in 5000°C. The wikipedia page says it will decompose at 500°C. Venus is an average of 482°C (900°F) at the surface. Hmm. Is SF6 a natural limiter for the temperature on Venus?

Wikipedia also says it forms by exposure of mineral sulphur with pure fluorine gas at room temperature. The following website says SF6 will form from F2 and S2 releasing 524kcal of heat.
http://www.sayedsaad.net/substation/sf6 … erties.htm

Interesting; is there a dynamic process where SF6 forms at mid-altutudes and breaks down near the surface? SF6 absorbs a great deal of heat as it breaks down, this sounds like the limiting factor at the surface.

The following paper requires payment, but there are interesting teasers in the abstract.
"Although 3700 naturally occurring organohalogens are now known to exist, only relatively few contain fluorine. The presence of several fluoroalkanes in volcanic and other geothermal emissions is well documented, although exactly how these compounds are produced remains a mystery. Also unknown is the impact that these natural fluoroalkanes have on the global atmospheric budget compared to their anthropogenic counterparts, since the concentrations of the natural compounds vary widely depending on the source. The remarkable ability of a few plants to sequester and convert fluoride into the highly toxic fluoroacetate and other fluorocarboxylic acids is well recognized, and the mechanisms for their formation are becoming understood. "
The brief quote cached by Google says "quantities of hydrogen fluoride in addition to hydrogen chloride.It is estimated ..... Harnisch J, Eisenhauer A (1998) Natural CF4 and SF6, on earth. ..."
This implies there is some natural formation/release of SF6 from volcanoes. All this means that, yes, SF6 formation on early Venus is highly feasible.
http://www.springerlink.com/index/DTPPVDHN6NKPNDNL.pdf

RobS · 2007-06-13 22:00:17

Has anyone done a search on the web for articles about primeval water levels on Venus? I am sure astrogeologists have made some estimates.

In making estimates, keep in mind that the sun started out COOLER than it is today, not HOTTER. It is steadily heating up as the hydrogen in core gets used up and the core compresses and heats up, which creates a larger core zone where fusion can occur and a faster rate of fusion (double the core temperature and you increase the fusion rate a lot more than double). That's why stars 100 times the mass of the sun burn out in just a few million years and a star ten percent the sun's mass lasts trillions of years.

I've only read the last four or five postings on this thread, but what I have seen seems to seriosuly need some scientific research.

-- RobS

StarDreamer · 2007-06-13 23:09:03

In making estimates, keep in mind that the sun started out COOLER than it is today, not HOTTER. It is steadily heating up as the hydrogen in core gets used up and the core compresses and heats up, which creates a larger core zone where fusion can occur and a faster rate of fusion (double the core temperature and you increase the fusion rate a lot more than double). That's why stars 100 times the mass of the sun burn out in just a few million years and a star ten percent the sun's mass lasts trillions of years.

I started to ask a question like this on the angular momentum thread, but I doubt anyone will pick up on that angle, so perhaps I should just come out and ask it straight: did the terrestrial planets start out much closer to the Sun? As protoplanets accrete mass, do they "walk" outwards in their orbits, sort of like the way a needle on a phonograph record player (oh man am I ever dating myself!) walks across the vinyl? When Earth got hit and Luna was born, that put more mass in Earth's orbit, so did the Earth then migrate a bit outwards away from the Sun? Which would then give some room to Venus to do likewise and push on Mars to nudge it a bit further out? Jupiter would not have budged at all, which is why we have an asteroid belt -- as the inner planets eased out a bit, that orbit go squeezed and could not pull together into a planet. Likewise, I have seen evidence cited to the effect that Uranus and Neptune formed late, perhaps a billion years after Earth.

Bode's Law may confound these ideas entirely.

If this is true, however, then Venus might have been closer and the greenhouse began then and Mars might have been closer (and thawed out and wetter) and then nudged into the deep freeze.

nickname · 2007-06-14 05:17:44

RobS,

Just the first 100 million to 500 million years of our stars first light up should burn much hotter than today.
Maybe as much as a billion years.

The initial gravitational balance will take at least 100 million years for our sun to settle in, and the early solar system would have many huge impactors hitting the sun on a regular basis.

After that turmoil dies down and the sun sets a balance then it cools quickly to less than it is today.

If the comet water delivery theory is correct it's about the same time as the bulk of the water was arriving to the inner solar system.

It's difficult to account for Earths water total in a 25% hotter early solar system without another water world colliding with it.

I expect Venus would have gone through the same process, it was just unlucky and had head on collisions and collisions that created retrograde moons.

If Venus has a couple of these collisions with other water hungry worlds we can get Venus to its current pressures pretty easily.

Adding water to a world with 40 or 50 bars of sulphur and c02 just makes a thicker co2 atmosphere.
3.5 billion years of that and we have todays Venus.
sulphur hexafluoride just makes it a much easier process and stops the water vapor to ocean world.

I think Robert should ask for a sulphur hexafluoride test of the current Venus:)
Think he might be on to something quite interesting.

StarDreamer · 2007-06-14 07:22:42

Hydrogen chloride will create a side reaction, but the monochloride is, however, a strong oxidant and readily hydrolyzed to sulfate.
SF4 + HCl + HF -> SF5Cl + H2
SF5Cl + 2 O2 + H2O -> SO4 + HCl + OH

Robert;
I was just looking at this equation again. Sorry, but where does the "F5" go in the second part? It fails to surface on the other side of this equation.

RobertDyck · 2007-06-14 08:47:11

Ok, I sent an email request to the European Space Agency (ESA) asking if the instruments on Venus Express can measure SF6. It is currently orbitting Venus. It has 3 instruments to means atmospheric composition: VIRTIS, PFS, and SPICAV/SOIR. SPICAV/SOIR will measure sulphur compounds in mid-altitudes (80–180 km), and VIRTIS will study the composition of lower altitudes (40 km to the surface) but doesn't mention sulphur. I asked if they will be able to measure sulphur fluoride in mid and low altitudes? SF6 has a density of 6.164 grams/litre so I expect it to accumulate in low altitudes.

RobertDyck · 2007-06-14 08:51:35

Hydrogen chloride will create a side reaction, but the monochloride is, however, a strong oxidant and readily hydrolyzed to sulfate.
SF4 + HCl + HF -> SF5Cl + H2
SF5Cl + 2 O2 + H2O -> SO4 + HCl + OH
Robert;
I was just looking at this equation again. Sorry, but where does the "F5" go in the second part? It fails to surface on the other side of this equation.

You're right. The website I got that from says "hydrolyzed to sulfate", I tried to flesh it out into an equation. I guess it should be:
SF5Cl + 4 H2O -> SO4 + HCl + 5 HF + H2

StarDreamer · 2007-06-14 09:23:18

You're right. The website I got that from says "hydrolyzed to sulfate", I tried to flesh it out into an equation. I guess it should be:
SF4 + HCl + HF -> SF5Cl + H2
SF5Cl + 4 H2O -> SO4 + HCl + 5 HF + H2

Okay, but HCl and HF is what we start with too. Where in these equations is the state of repose or of equilibrium, where the reactions stop and the products come to rest? Maybe it just depends how much of which is available in the Venus environment. Whichever element gets exhausted first determines the end-state?

From what I have heard, fluorine in any form is highly reactive and toxic. I can't see HF (or HCl either!) just sitting around doing nothing. So we could sequester the sulphur into sulphate, but will it stay there? And then what do we do with these other reagents?

Or are you saying that the answer for venus is more water and lots of it to take out the sulphur as sulphates? But the atmosphere has lots of H2SO4, which is sulphuric acid, yes, but also hydrogen sulphate, technically. so perhaps this equation is:

SF5Cl + 4 H2O -> H2SO4 + HCl + 5 HF

The H2SO4 we have, but I don't know that anyone has detected an abundance of HF in venus (at 5:1 ratios to the vitriol).

(my high school chemistry is coming back to me!)

RobertDyck · 2007-06-14 10:51:25

No, that won't sequester carbon dioxide or significantly reduce the atmosphere. What I think is happening now is a series of reactions until a stable compound is formed. SF6 is stable, non-toxic, inert, safe. It's a clear, colourless, odourless gas. However, it is an extremely powerful greenhouse gas that will trap heat in, warming Venus. Until it reaches 500°C, at which point it decomposes, acting as a powerful refrigerant. This regulates the temperature to at or just a touch below 500°C, which is what we see.

Terraforming will require converting CO2 into something solid. In high school I thought of converting CO2 into a ring molecule, C3O6; a six-member ring with O alternating with C, and each C double bonded to another O. A chemist friend said it would be unstable; electron affinity would tend to break it down into CO2. I don't know, would like to try it. Another alternative is a polymerized carbonyl sulphide; ideally a copolymer with pure carbonyl. Sounds great, would scrub CO2 without consuming hydrogen. Could you get it to work? Acid anhydride is represented as: R-CO-O-CO-R. So that ring molecule is just pure anhydride as a ring. Could you polymerize anhydride with the occasional sulphur atom instead of oxygen? Or could you just polymerize ethanoic anhydride? That's C4H6O3 also represented as CH3COOCOCH3. If you polymerize anhydride groups with CH3 terminus at each end, it could sequester a lot of carbon dioxide.

I would genetically engineer an anaerobic bacterium to live in the clouds and excrete the compound we need to sequester CO2.

StarDreamer · 2007-06-14 11:49:20

This is getting very interesting ....

Lime (CaOH) is used to scrub H2SO4 from industrial chimneys, resulting in the production of pure gypsum (CaSO4) and water, via:

H2SO4 + CaOH -> CaSO4 + H2O + H-
(so you actually need to double the recipe to complete the H ion)

But CaOH will precipitate out CaCO3 in the presence of CO2. And it decomposes at temps of 512°C.

CaSO4 is highly insoluble in water, so therefore dropping calcium on Venus should scrub the atmosphere of sulphur and release the water as well as lots of hydrogen. I think there are some varieites of sulphur-eating bacteria, yes?

But then read: http://en.wikipedia.org/wiki/Sulfate
which talks about the contribution of aerosol sulphates to Earth's albedo and the masking of incoming sunlight (insolation), resulting in "global dimming": http://en.wikipedia.org/wiki/Global_dimming

Sulphates in the sky will promote cloud formation and discourage rain droplet formation, hence extending cloud longevity. Sulphates are suspected of promoting droughts on Earth and the decrease in sulphates since the collapse of Cold War industry in Eurasia may be responsible for the acceleration of global warming and megastorm systems.

How much of this applies to Venus? Global cloud cover and no rain.

What element could we transport to Venus to provoke a global endothermic reaction?

RobS · 2007-06-14 11:50:46

Boy, that would be a lot of solid carbon compound on the surface! If the Venus atmosphere is almost pure CO2 at 100 atmospheres of pressure, that would be about 1,000 meters of solid at a density if 1 gram per cubic centimeter. I hope the compounds are solid enough to build houses on them! Would trees be able to grow in it?

I think the early models of Vensus's surface often assume an ocean because it is hard to imagine Venus receiving that much CO2 and not a fair amount of H2O at the same time. There was a brief TT Tauri phase when the sun was hot, but it didn't last long; not hundreds of millions of years.

Someone asked whether planets formed closer to the sun and moved outward over time. The literature I have read suggests the opposite: they form farther out and move inward over time. I gather that when a planet and an asteroid have a close encounter, the result on their orbits does not average out to be neutral; while sometimes the planet slows the asteroid down and sends it into a lower orbit, more often it sends it into a higher orbit or even ejects it from the solar system. That results in the planet spiraling inward. This is one mechanism that explains "hot Jupiters." Another is drag in the residual solar nebula on the orbits of planets.

-- RobS

RobertDyck · 2007-06-14 14:36:32

Hah! Found out more data on this stuff. As a polymer without sulphur it's called polyanhydride and is used for medical implants. It's a biodegradable polymer, the body will absorb it. It's also biocompatible. Ok, so that tells me it's not toxic.
Wikipedia: Polyanhydride

With sulphur instead of oxygen binding the alcyl groups it's called thioanhydride, or anhydrosulfide. End groups are everything, it can have immunological effects and one thioanhydride is a medication. Maybe stick to pure polyanhydride.

Now immagine the ground covered in a plastic dust metres thick, as thick above bedrock as dirt on Earth. Plastic dust that biology will decompose so acts as a rich carbon soil for plants and microbes. You should be able to build a house on it as long as the compound doesn't break down too quickly, or form a gas. If it's a long chain polymer (say as long as starch: up to 100,000 monomers) it would probably be white. White until contaminated with something. So white plastic dust soil, short on nutrients like nitrogen, potassium, phosphorus or trace nutrients. Trace nutrients can be added by rock flour (rock ground to fines). With several times as much nitrogen gas as Earth, legumes innoculated with rhizobium bacteria can fix nitrogen. After a full biosphere grows, atmospheric nitrogen would probably be reduced to match Earth.

I'm reminded of a 1980s TV program called ALF. He was supposed to be from the planet Melmac.

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