Life in Venus' upper atmosphere - Does Venus have life?

REB · 2004-05-03 12:59:43

http://www.popsci.com/popsci/aviation/a … -1,00.html

Venus having life sounds crazy, but after reading this very good article, it sounds convincing.

Many of you have heard the story about the story about the unaccountable absorption of UV rays in Venus upper atmosphere. This article goes a little deeper.

DonPanic · 2004-06-04 04:26:29

LO
It would be funny that life was to be found on Venus when most would have bet on Mars

atomoid · 2004-06-04 17:10:16

excellent article, some interesting highlights:

- 53 kilometers up, where the temperature is a mere 110°F, atmospheric pressure is less than Earth's at sea level, and there is a soup of chemical compounds and plenty of light to facilitate the extraction of energy from the soup.

- Venus likely had oceans in its early years, for a few hundred million to a couple of billion years, back when the sun was 30 percent less hot. If you want to think about the best place, 4 billion years ago, to start life (in) this solar system, it would probably be Venus, then, as the sun grew more intense, carbon dioxide and water vapor trapped the heat, conditions spun out of control, the seas boiled off.

- 700 million years ago a cataclysm occurred: Fissures opened all across the planet's crust, and lava covered everything: a global resurfacing event. To this day, lava flows regularly scorch the planet's surface.

- An organism could get energy from the Venusian atmosphere by a multi-step process which uses sulfur dioxide and carbon monoxide to create formaldehyde, sulfur, and energy. Those reactions would explain the low concentration of carbon monoxide on Venus. Intriguingly, this sulfur nutrient cycle could also provide insight into why some forms of sulfur persist when they should have reacted away long ago—an imbalance, a disequilibrium, that indicates that something is injecting energy into the system.

- anomalous Y- and C-shaped bands in Venus' atmosphere. The structures were first clearly observed 60 to 70 kilometers above the surface of Venus by Mariner 10 during a 1974 flyby, and, for some reason astronomers can't explain, absorb ultraviolet light. microbes in the Venusian clouds may have found a way to photosynthesize using UV light instead of the gentle visible bands found on Earth. If this were true, it would help explain another eccentricity of Venus. While the planet turns at an agonizingly slow pace—a full day/night cycle on Venus takes 243 Earth days, a long time for a life-form to wait for the next dawn—its upper atmosphere swirls round in a mere four Earth days, more than 60 times faster. These UV-absorbing microbes would not only explain the high-altitude bands in the atmosphere, but might explain the atmospheric superrotation as well. UV-absorbing microbes could generate distinct hot and cold fronts. These fronts in turn would create a convection cycle, the intense pressure gradients fueling an extra-speedy atmospheric rotation.

Shaun Barrett · 2004-06-04 19:55:47

Thanks, Atomoid!
That was a great summary.
This is actually the first time I've ever heard of the concept that bacteria in the Venusian atmosphere may actually be creating the conditions which ensure their survival. The idea of microbes altering the energy absorption in the 'air' around them and creating convection currents resulting in atmospheric super-rotation, is a fascinating one. It sounds like a lower-order analogue of the terrestrial "Gaia" theory - life creating the environment for life.
My view of the solar system, which encompasses the frequent exchange of life-bearing crustal material among the planets due to impact transfer, can readily accommodate such a scenario for Venus. It isn't even necessary for Venus itself to have spawned life independently, although it certainly could have.
In my model of the solar system, it's quite probable that there is bacterial life (at least) in many places. And it could quite easily be derived from just one original source - maybe from Venus, maybe from Mars or Earth, or even conceivably from another star system entirely, if Hoyle and Wickramasinghe's panspermia hypothesis is feasible!
I believe life will be found on Mars and it will most probably be bacterial/archaean with the same biochemical signature as terrestrial life. If this 'new' Venusian picture turns out to be accurate, then again I foresee the organisms involved being essentially the same as those on Earth and Mars - the same 20 amino acids and the same chirality.
Just a few thoughts.

lunarmark · 2004-06-07 04:58:42

I have always thought Venus to be a far better candidate than Mars for life (lets face it, Mars has practially no atmosphere!!) - Venus however is a veritable chemistry set perfect for forming life (at least higher in the atmosphere), youv'e got methane, water co2 sulphur etc at decent pressure. Even at the surface whilst its typically over 400 celsius, -well below the surface it may very well be cooler?

There are bacterial forms on earth that survive many hundreds of degrees I see no reason why Venus couldnt support some sort of life, (earth is very similar in geology and size).

I am just staggard at the complete lack of any decent missions to the Venusian surface. Surley in this day and age, it should be possible to land a probe that can take the heat?

All it needs is a Titanium insulated pressure vessel with a coolant inside! The trick would be to store enough coolant (e.g Solid Co2 or Liquid Nitrogeon) to last the misson. And to start with, land it on a mountian top!

Personally I would land a lander with a bell shaped 'enviromental dome', that a hardened rover could crawl around underneath (and this dome could protect it), you could even have some sort of cooled enviroment under the dome, (like a diving bell) this would allow more delicate machinery to examine the surface soil, without heat and acid spoiling the day.

Shaun Barrett · 2004-06-07 07:52:17

Yes, Lunarmark. It would certainly be fascinating to investigate the surface of Venus for longer than a matter of minutes.
In theory, it's possible to refrigerate a probe on the Venusian surface for as long as you like - provided you have the machinery to create a sufficiently large temperature gradient between the inside and the outside, and the power supply to run the machine.
I suppose, if you had a powerful nuclear reactor and a refrigeration arrangement efficient enough to pump heat from the probe, and excess heat from the reactor, out into the Venusian environment, you could cruise around on Venus for months.

I guess the main problems are launch weight and, therefore, money. And what if all you found was hot basalt?!!
???

lunarmark · 2004-06-07 09:44:08

I spose the ultimate mission has to be a Venus sample-return, I guess thats pretty tricky due to the atmosphere and gravity though!

My thought would be that the surface would be pretty much basaltic since the surface is very young by geological standards, and any interesting minerology would be cracked and melted in the heat.

I would have thought though with all that sulphuric material raining down there would be a lot of FeS (Iron Sulphur) minerals too (ideal for some Microbes), the high temperature would probably mean that the supposed 'acid rain' would turn to vapour long before reaching the ground, so you would actually have a heavy sulphurous vapour/cloud hanging around several miles above the ground. So actually the surface may be just baked basalt.

Venus fits all classical descriptions of Hell, thats for sure. We should really swap the names of Mars and Venus over

atomoid · 2004-06-07 20:41:19

I havent spent much time thinking about Venus until i read this thread, ive got to admit im pretty ignorant of basic Venus facts and ask the following newbie questions:

- Does anybody know why venus rotates as slowly as it does? is it just that all the other planets happened to get whacked early on by planetoids which imparted the spin in the first place. A Venus day is 243 Earth-days and, get this, it spins backwards compared to the rest of the planets. a Venus year is 225 earth days. if it didnt spin at all then its day would be 243 days since the full orbit would mimic one day. whats up with that?

- Do the clouds transport heat really quickly around the planet? I'd expect the dark side of venus to get pretty cold, with tons of snow and ice forming as the atmosphere comes streaming in to fill the gradient, the greenhouse effect cant be that efficiently insulating can it? i'd expect the poles to be somewhat protected from the heat as well, are the winds belted like on the gas giants or just swirling around everywhere to make venus pretty uniform temperature? id expect some pretty steep temp gradients in a world like this. its really intriguing.

- where does the present day vulcanism come from? Earth has a moon and plate tectonics to account for most of its vulcanism, Venus has no such "stirring" mechanism, perhaps its just residual heat from formation released during brief and rare "plume" episodes. Is there a magnetic field? if so, it would suggest a lively convecting core, if not, where could the vulcanism-driving heat come from?

Shaun Barrett · 2004-06-08 01:06:12

I don't think Earth's vulcanism is caused by its tectonics; rather, it's the other way around, the tectonic activity is driven by vulcanism. There is a degree of tidal flexing due the Moon but it's not enough to cause the kind of heating we're talking about here. Most of that comes from residual heat of formation supplemented by the heat from radioactive decay of unstable isotopes in the body of the planet.
I believe tectonics here on Earth enable our planet to release its internal heat in a series of relatively benign eruptions and outgassings, together with recycling of the crust.
It's water that lubricates the tectonic plate movements on Earth but Venus lost nearly all its water ages ago, so Venus' plates, if it ever had any, are fixed in position. Perhaps this is why our 'sister planet' experiences periodic convulsions like the one you referred to, which occurred 700 million years ago and which resurfaced almost the whole planet.

From memory, the night side of Venus is not substantially cooler than the day side, though the highest mountain peaks are a little less hellish than the low points!

Some people speculate that Venus may have had a much faster prograde rotation to begin with but that a major impact with a large planetesimal caused its present very slow rotation rate.
I find the subject of planetary rotation rates very interesting - particularly the amazing coincidence that the martian and terrestrial days are almost identical. I once did a rough calculation regarding Earth's slowing rotation rate (which is due to transfer of angular momentum in the Earth-Moon system as Luna raises tides on Earth's surface) and found that Earth's day will be the same length as Mars' day in about 180 million years. If we wait until then, we won't have to worry about adjusting our watches when we visit Mars!

Hazer · 2004-06-08 01:10:27

From http://starryskies.com/solar_system/ven … _venus.htm

"The atmosphere of Venus is about 250 km (155 mi) thick. The atmosphere circulates in a westerly direction about every 4 days.
The windspeed in the highest cloud layer reach 355 km/hr (220 mi/hr) which is roughly equal the Earth's jet stream.

The middle cloud layer has the fastest winds. These winds can reach 724 km/hr (450 mi/hr.) That is faster than the fastest tornado on Earth!

In the lowest cloud levels, the winds blow at around 160 km/hr (100 mi./hr) Then, at the surface there is a gentle breeze of only 3.6 km/hr (2.2 mi./hr.)"
------------------------------------------

Well atomoid, seems you were spot on about the clouds transporting heat around the planet, those are some pretty darn fast mid-level winds.

Think of the thermal energy that is required to cause a substance to vaporize at 90 atmospheres--it's a lot. Consequently, those clouds should keep the temperature pretty much constant planetwide. (Now if we could only find a way to remove carbon from it en masse...)

"Venus fits all classical descriptions of Hell, thats for sure. We should really swap the names of Mars and Venus over."
Really? I've always heard that war is hell. Sex isn't, there's really no reason to swap the names over.

If we do do some more missions to Venus, we ought to do aerial-photography from the mid levels with high-powered balloon mounted cameras that resolve down to less then a meter.

Yang Liwei Rocket · 2004-06-08 02:48:50

anyone watching the Transit, check this dude. He's just got a pic, holding bino's and projecting the sun on a piece of paper and then taking a photo

http://img1.tapuz.co.il/forums/33306614 … 306614.jpg

atomoid · 2004-06-08 19:09:42

I don't think Earth's vulcanism is caused by its tectonics; rather, it's the other way around, the tectonic activity is driven by vulcanism...
...It's water that lubricates the tectonic plate movements on Earth but Venus lost nearly all its water ages ago, so Venus' plates, if it ever had any, are fixed in position. Perhaps this is why our 'sister planet' experiences periodic convulsions like the one you referred to, which occurred 700 million years ago and which resurfaced almost the whole planet...

I think theres some sort of consensus that techtonic activity does actually cause the bulk of vulcanism on Earth (aside form hotspots like Hawaii). Not that their not closely interdependent but the idea of the continents being rafted around by currents in the underlying lava i think has recently given way to a model in which you have what is called a "slab pull" component which is actually quite a bit more dominant than the "pushing" currents themselves. As the leading edge of a continent subducts under another continent, this material by its weight actually pulls the continent along with it, all the lighter components melt and float up and create most of the volcanoes in the world such as the pacific "ring of fire". I have not heard any mention of water lubricating the plates but it probably plays some sort of role.

I read a really compelling article once (i think it by one of the "Rare Earth" people, the point of the article was to suggest that conditions for life are extremely far-fetched) that suggested that the reason Venus doesnt have plate tectonics is because it didnt have a planetoid smash into it. In Earth's case a planetoid spalled the bulk of its crust into orbit (to become the moon) thus freeing up the surface of the earth to get plate tectonics working. Without such an event he sugests the crust is locked-up and plate tectonics is impossible. I did read somewhere that Venus has "continents" im not sure what those really are though.

...the amazing coincidence that the martian and terrestrial days are almost identical. I once did a rough calculation regarding Earth's slowing rotation rate (which is due to transfer of angular momentum in the Earth-Moon system as Luna raises tides on Earth's surface) and found that Earth's day will be the same length as Mars' day in about 180 million years. If we wait until then, we won't have to worry about adjusting our watches when we visit Mars!

Wow, i've always been amused by the similar day length too, Earth's day length change you mewntion is such an eyeblink in geologic time, it makes you wonder how short Earth's day was a few billion years ago when life first appeared...?

i just noticed http://www.spacedaily.com/news/early-earth-04h.html]an interesting article that i havent read yet, but sounds somewhat pertinent

lunarmark · 2004-06-09 04:26:05

Saw the transit myself, fantastic. A real treat!

'Venus is the god of love, mars the god of war - the planet mars is tranquil, Venus is a violent hell - Hello, wrong name alert '

What I dont understand about venus, is if it has no magnetic field (as such) then how does such a massive atmosphere stay attached to the planet?

Surley accepted wisdom is that a magnetic field repels/diverts the solar wind away, stopping the atmosphere/gas molecules from being stripped off (this is essentially why mars has next to no atmosphere)

Shaun Barrett · 2004-06-09 07:58:39

Thanks, Atomoid. Interesting idea, this 'slab pull' thing - I don't think I've ever heard the term before. It certainly sounds feasible and I think your comment that tectonic activity and volcanism (sorry, I believe I misspelled it above) are mutually conducive is probably a fair evaluation of the situation.
As for water in the subducting crust lubricating the plates, I believe this is a widely accepted theory. Without the water, friction would bring most of the sliding plates to a halt until the pressures became titanic. As I mentioned, Venus doesn't have enough water for this and its hypothesised periodic episodes of catastrophic volcanism have been attributed to just such long-term pressures causing unimaginable volcanic eruptions - perhaps in a 700 million year cycle.

I have a book called "The History of Earth", by William K. Hartmann and Ron Miller. If you find it in your local library, it's worth spending a few minutes thumbing through it.
It suggests that calculating backwards, using the Moon's known rate of recession from Earth, it's possible to determine with some degree of accuracy how fast Earth must have been rotating just after the Moon-forming collision occurred about 4.5 billion years ago. Apparently, a day was only about 5 hours long - 2.5 hours of daylight followed by 2.5 hours of darkness!
This situation didn't last long, of course, because the Moon was so close that it raised simply enormous tides, probably of magma at first and later of water, which swept around the planet at proportionately high speeds. The major frictional drag involved caused a rapid transfer of angular momentum from Earth to the Moon, which consequently moved quickly away from Earth. In other words, the days lengthened much more quickly at the beginning than they're doing now - it hasn't been a linear process.

With Mars, it's not currently possible to know how its rate of rotation may have varied in the past. There's no high-mass moon receding steadily from the planet to use as a gauge. And, if Phobos and Deimos are the only moons Mars ever had, they would have had a negligible effect on Mars' rotation rate over the eons.
I sometimes look at vast impact basins like Argyre and Hellas, though, and speculate as to how the events which caused them could have altered the length of a martian day. To me, the fact that Earth and Mars have nearly the same day-length, is as astonishing as our Moon and the Sun being exactly the same apparent size as seen from Earth at this particular moment in time - a time when an intelligent species happens to have arisen here with the awareness and the technology to appreciate the cosmic coincidence!

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#1 2004-05-03 12:59:43

Re: Life in Venus' upper atmosphere - Does Venus have life?

#2 2004-06-04 04:26:29

Re: Life in Venus' upper atmosphere - Does Venus have life?

#3 2004-06-04 17:10:16

Re: Life in Venus' upper atmosphere - Does Venus have life?

#4 2004-06-04 19:55:47

Re: Life in Venus' upper atmosphere - Does Venus have life?

#5 2004-06-07 04:58:42

Re: Life in Venus' upper atmosphere - Does Venus have life?

#6 2004-06-07 07:52:17

Re: Life in Venus' upper atmosphere - Does Venus have life?

#7 2004-06-07 09:44:08

Re: Life in Venus' upper atmosphere - Does Venus have life?

#8 2004-06-07 20:41:19

Re: Life in Venus' upper atmosphere - Does Venus have life?

#9 2004-06-08 01:06:12

Re: Life in Venus' upper atmosphere - Does Venus have life?

#10 2004-06-08 01:10:27

Re: Life in Venus' upper atmosphere - Does Venus have life?

#11 2004-06-08 02:48:50

Re: Life in Venus' upper atmosphere - Does Venus have life?

#12 2004-06-08 19:09:42

Re: Life in Venus' upper atmosphere - Does Venus have life?

#13 2004-06-09 04:26:05

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#14 2004-06-09 07:58:39

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