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I made some minor changes to references; I also deleted a sentence that mentioned the albedo of Venus is 0.76 since one sentence later stated that Venus reflected 90% of the incident sunlight. The alternative to deleting this sentence would have been a long discussion of the different types of albedo (which varies with wavelength), which would have been rather off-topic; people actually interested in albedo can look at the albedo entry.
Geoffrey.landis 15:13, 12 September 2006 (UTC)Geoff Landis
"Hydrogen is primarily present as sulfuric acid (H2SO4), and hydrogen can easily be extracted through condensing the droplets."
Sulfuric acid does not release any hydrogen by "condensing" the droplets. On the contrary, sulfuric acid attracts and holds any water violently. Perhaps this is the reason why there is any trace of water on Venus left at all. 84.160.239.47 22:17, 17 November 2006 (UTC)
The article has several apparent contradictions that need to be explained in footnotes if not the main text ie "sulfur dioxide is 150 parts per million." No mention of sulfur trioxide which should be in surplus if there is "no water." It says 6 parts per million of water vapor in another part of the article. I suppose the problem is the composition of Earth's atmosphere is typically given as gas-only and particulates such as dust, sulphuric acid, ice, and water droplets are discussed separately. Also, Earth atmosphere scientists typically include the carbon dioxide vapor percentage, but not the water vapor percentage; just the opposite of how we have figured Venus, perhaps because the lower atmosphere of Venus is hot enough that carbon dioxide is a gas, not a vapor, as it is in Earth's atmosphere. Neil
The text includes the conjecture that Venus' atmosphere is composed of largely carbon-dioxide and nitrogen mixture because of the lack of a strong magnetic field, lighter gases not being held because of the lack of a strong magnetic field as Earth has. That would hold true also for Mars, which has a larger carbon dioxide-nitrogen atmosphere (if much thinner).
A simpler explanation exists: Venus is hot. Magnetic fields do not hold gases so effectively as does gravity. The Earth has high enough gravitation and cooler temperatures to hold gases as light as methane, ammonia, and water vapor. To be sure, the Earth's atmosphere holds little methane or ammonia because of thermodynamic instability in an oxygen-rich environment, but it holds water vapor very well. It's, of course, gravitation. A strong magnetic field may prevent some chemical reactions in the Earth's upper atmosphere, preventing the formation of such substances like sulfuric acid, but that is a different topic.
Venus is much hotter at its surface, hot enough that with gravity slighter (but not by much!) than the Earth's, Venus cannot hold gases as light as methane, ammonia, and water vapor. Much chillier than Earth, but with far lesser gravity, Mars likewise cannot hold water vapor. With their combinations of temperature and gravitation, both Mars and Venus can hold atmospheres consisting largely of carbon dioxide and nitrogen. -- Paul from Michigan 01:49, 25 November 2006 (UTC)
Life is of course a non-equilibrium state. Under equilibrium, water would react with carbon and carbon compounds to form carbon dioxide, and with sulfur and sulfur compounds to form sulfuric acid. As is well-known one can place carbon and sulfur in cold water and have no reactions.
Biochemistry itself suggests that life formed on Earth from a mixture of substances, some of which would not exist long in an oxygen-rich environment. Of course, water, carbon oxides (whether carbon monoxide or carbon dioxide), and phosphates exist. But most biochemical substances are methane derivatives. Ammonia and hydrogen sulfide would have to have existed.
Living things (plants) can synthesize methane derivatives from carbon dioxide and water and can transform nitrites and nitrates into ammonia. Some bacteria 'fix' nitrogen. But that is life at work.
Most predictions of the future of the Earth suggest that as the sun becomes more luminous, that unless the Earth's orbit becomes adequately displaced from where it is now (I believe that if humanity or some intelligent successor is around, that creature is likely to force the Earth into orbit progressively more distant from the sun as needed), the Earth will get hotter. The Earth is toward the warm end of the life zone, and when the normal temperature on Earth approaches 45C, life will be in big trouble. Much of the biomass will die and become fuel for spectacular forest and brush fires that will thrust more carbon dioxide into the atmosphere, accelerating global warming. Higher evaporation of water will have added another greenhouse gas -- water vapor -- into the atmosphere. Atom for atom, water vapor is an even more powerful greenhouse gas.
Around 70C, the 'wet greenhouse' effect that some say occurred early on Venus takes off, and the Earth's atmosphere itself takes on the characteristics of a pressure cooker. Meanwhile, the greater pressure of the atmosphere causes the atmospheric temperature to rise in accordance with the gas laws. The process accelerates as more of the waters of the sea evaporate into the atmosphere. Some water vapor goes to the upper atmosphere and some water molecules dissociate into oxygen and hydrogen, hydrogen going off into space. Until the seas are evaporated away, there's more water vapor available to replace the water dissociated into oxygen and water.
At 305 C, the critical temperature of the water, liquid water no longer exists. By then, even if the Earth has gigantic clouds protecting the planet from sunlight, pressure alone creates hothouse conditions. (Venus is hot because of the pressure of its atmosphere -- not because of the intense sunlight that shines upon cloud layers that insulate the planet). Carbonate rocks decompose, releasing carbon dioxide, and pressures lead to temperatures high enough to melt surface rocks.
Gory, isn't it? The earth's atmosphere would be full of oxygen from dissociated water, carbon dioxide first from the burning of biomass and petroleum, and then especially the release of it from carbonate rocks, sulfuric acid from the burning of sulfur and sulfur compounds, a little nitrogen, and some water vapor. The Earth could get even hotter than Venus is today -- hot enough to melt all rock surfaces. That's all long before the Sun flares off the atmosphere and beats down upon the exposed surface of the Earth.
That all depends upon the extinction of complex life. We might not have the means -- yet -- of altering the Earth's orbit. But humanity or whatever its successor at the time (advanced pigs?) will likely cherish life enough to get the Hell out of an infernal prospect. The Gaia effect got little chance on Venus or Mars. It may need some help a few hundred million years hence just to continue. Sure, this is speculation, and as such 'original research'... probably forgivable in a talk page. -- Paul from Michigan 10:20, 14 January 2007 (UTC)
The magnetic field doesn't hold in hydrogen, it shields a planet from the solar wind that would slowly scrub the hydrogen away into space. To address your question about sulfur trioxide, I believe the UV-initiated reaction in the upper atmosphere is CO2 + SO2 -> CO + SO3. And then SO3 + H20 -> H2SO4. So there is not an excess of SO3, it recombines with carbon monoxide given the chance. DonPMitchell ( talk) 03:55, 9 August 2008 (UTC)
I agree the clouds might cause most of the greenhouse effect, since they cause the radiating surface to be at a high altitude. Adiabatic compression can then heat the atmosphere below with the very high surface pressure. I've yet to find this in any journal articles, though I have seen this in a presentation by Ned Nikolov that is online. The CO2 might cause an addition 100C or so if we make the approximation of extrapolating the logarithmic dependence we see on Earth. — Preceding unsigned comment added by 2601:281:8200:98AA:C8F2:7A2B:D7AC:466D ( talk) 02:29, 19 February 2019 (UTC)
How much hotter is Venus than Earth?
It's a lot hotter if you compare surface temperatures to surface temperatures -- 288K to 750K. But, if you compare atmospheric temperatures at the same pressures, say at 1 Bar, the difference is a lot less dramatic. Earth's 1 Bar temperature is 288K while Venus' is 360K. If you also subtract out the extra temperature due to Venus having to shed more heat from solar radiation, the difference in atmospheric temperature is around 20 K -- a whole lot less than the almost 500-degree difference in surface temperatures.
This means that the extra heat at the surface is coming from adiabatic compression (extra pressure), not from extrasolar radiation or the greenhouse effect. I've written up an article explaining this more fully and posted it at
www.whiteworld.com/technoland/stories-nonfic/2008-stories/Venus-temp.htm
I'd like to get an external link reference put in this article if I could.
Cyreenik 15:31, 12 April 2007 (UTC)
Cyreenik: A link to your "article" would constitute Original Research. In any case, it's well documented that the extreme surface temperatures on the surface of Venus are due primarily to the huge amount of carbon dioxide, a greenhouse gas, in Venus's atmosphere, in other words, to global warming. "Atmosphere temperature" is--obviously--largely beside the point. TheScotch ( talk) 22:42, 20 December 2017 (UTC)
WP:Good article usage is a survey of the language and style of Wikipedia editors in articles being reviewed for Good article nomination. It will help make the experience of writing Good Articles as non-threatening and satisfying as possible if all the participating editors would take a moment to answer a few questions for us, in this section, please. The survey will end on April 30.
At any point during this review, let us know if we recommend any edits, including markup, punctuation, and language, that you feel don't fit with your writing style. Thanks for your time. - Dan Dank55 ( talk) 21:05, 11 April 2008 (UTC)
I've signed up to review this, and I'll put comments when I get a chance for a thorough read Jimfbleak ( talk) 11:05, 29 April 2008 (UTC)
Jimfbleak ( talk) 16:05, 29 April 2008 (UTC)
Nice article and a good read Jimfbleak ( talk) 09:56, 30 April 2008 (UTC)
From this image I thought Venus' surface level is below Earth's ocean level at 50 meters below. Venus has 3 levels of cloud layers, and the haze lies between each cloud layer. Do someone want to clarify this image a little bit.-- Freewayguy What's up? 20:15, 29 August 2008 (UTC)
I am not an astronomer or physicist, so I may sound idiotic, but shouldn't it be specified whether the elemental composition given in the table is molar or by mass? After all, if in one kilogramme of the Venerian atmosphere there is 965 g of carbon dioxide, this is not the same as saying that in one mol of Venerian atmosphere molecules, 96.5% will be carbon dioxide molecules.
Edit (different person): hyper physics has CO2 in the Venusian atmosphere at 96.5% by volume. I don't know how sources are qualified on Wikipedia (I don't edit, myself), but the values are the same. Could be a good lead on a better citation.
http://hyperphysics.phy-astr.gsu.edu/hbase/Solar/venusenv.html — Preceding unsigned comment added by 130.184.252.75 ( talk) 19:47, 8 June 2019 (UTC)
Particularly, the section referencing carbonyl sulfide... if you reference http://en.wikipedia.org/wiki/Carbonyl_sulfide, it appears this molecule is created from geothermal vents and volcanoes, and readily forms in the presence of CO and S, not a likely candidate to say that it's an "unambiguous indicator of life"
Thoughts? —Preceding unsigned comment added by 66.104.60.6 ( talk) 15:49, 17 August 2009 (UTC)
Today I unsuccessfully attempted to edit this page so that the surface temperature would be in both Fahrenheit and Celsius, rather than just Celsius and Kelvin. Temperatures are supposed to provide a reference point. All articles on Wikipedia are supposed to be written for a general readership, not specifically for scientists. Most Americans aren't familiar with Celsius, and Kelvin is something restricted to scientific use. My suggestion was to list in F and C and then put K over in the information panel because Wikipedia isn't a scientific journal. Someone in the page edit history argued that it isn't necessary to add Fahrenheit for temperature greater than boiling water. That doesn't make any sense. 250 degrees K is cold. But most Americans upon seeing that number would probably think it meant "hot." Sadly, most Americans also couldn't tell you where water boils and freezes on the Celsius scale, and the scales also differ in sensitivity. For example, there are only 100 degrees between the boiling point and freezing point of water on the Celsius scale, but there's a 180-degree span on the Fahrenheit scale. For millions of ordinary people in the U.S., then, these numbers are rather meaningless unless they find a way to convert them to the scale they're used to.
Encyclopedias are for general reference, even the scientific articles. And the standard for a general reference in the U.S. is to list in both Fahrenheit and Celsius. For example, see what Encyclopedia Britannica does here. Also, see how NASA displays it for a general audience [www.nasa.gov/worldbook/venus_worldbook.html here]. Danrz ( talk) 18:37, 4 December 2009 (UTC)
I don't agree with what you think the policy is as it applies here. I know what the convention is and I just showed you what NASA and Encyclopedia Britannica do in the above links for a general readership. And I never said Kelvin shouldn't be on the page. I wanted all three, with Kelvin in the side panel. That's how it is on the Mars page, and Mercury. And scientists will even talk about it in Fahrenheit when speaking to general U.S. readers so that the readers know what s/he is talking about -- e.g. see here and U.S. science magazines that aren't targeted to scientists also list the temperature in Fahrenheit -- see here. Danrz ( talk) 20:39, 4 December 2009 (UTC)
So your most recent argument(after making others in the edit history) is that the USA is eccentric and that it doesn't merit putting the degrees Fahrenheit in parentheses. And in your most recent edit, you hyperlinked the "K", sending all the readers who have no idea what the number really means over to the Wikipedia Kelvin page where there's a formula that they can use to convert it to Fahrenheit -- instead of just putting the Fahrenheit in the article itself. I don't consider that helpful. Danrz ( talk) 20:39, 4 December 2009 (UTC)
Didn't you all know the netric system is a commie plot? — Preceding unsigned comment added by 162.192.181.76 ( talk) 04:45, 18 October 2013 (UTC)
Can someone explain how the hell Venus is supposed to have an atmosphere 100 times heavier than that of the Earth, while Venusian surface gravity is 90% of the Earth's? Either the force of gravity on Venus is much, much stronger or is composed of molecules with a mass, which is not indicative of a gas, but rather of a solid. I will do the exact math later. 62.33.188.17 ( talk) 00:22, 25 December 2009 (UTC)
Thus, the atmospheric pressure at the surface level of Venus should be no more or less than that of Earth's. 62.33.188.17 ( talk) 15:33, 25 December 2009 (UTC)
To answer the original question, Venus has a lot of outgassing due to volcanism. The resulting high temperature and atmospheric pressure prevent CO2 from being fixed into carbonate rocks the way it is on Earth. Of course, that still leaves us with a mystery as to the original cause: Why did Venus have such a freakishly large amount of volcanism, at least in the recent past? This appears to relate to the lack of plate tectonics, which leaves volcanoes the only mechanism to relieve heat or pressure in the interior. Kauffner ( talk) 13:22, 7 January 2011 (UTC)
The figure of 33 C for the terrestrial greenhouse effect is given all over, by almost everyone who discusses this issue. ("Without this effect, the earth would be about 33 C colder than at present." [2]. See also the greenhouse effect article, which cites the IPCC on this.) As for the rest of the sun's heating effect, sunlight is absorbed by the surface and warms it. This heat is transferred to the gas in contact with the surface, both greenhouse, and non-greenhouse. Then the atmosphere is warmed by convection. This allows heat to be retained through the night, etc. Why Venus is so hot is one of the outstanding mysteries of science, so I obviously can't give you a fully satisfactory answer. Significant heat must come from the interior, from volcanism and tectonics. On Earth, the Cretaceous was outstanding for its volcanism, with a superplume in the South Pacific and massive sea-floor spreading, and was also far warmer than today. At Venusian pressures, CO2 has quite different properties than it does on Earth. Less than 30 cm will absorb IR entirely, so there is an insulating effect. Kauffner ( talk) 04:03, 8 January 2011 (UTC)
Ruslik_Zero: Thanks for the link to the Science article abstract. What they meant is certainly clearer there than in the news article. You could dial down the snark, though, since just a little while back you were asking basic physics questions like how convection could heat.
Kauffner ( talk) 04:53, 9 January 2011 (UTC)
The lapse rate is an empirically derived description of the temperature pattern, not an explanation for it. Yes, I know what the greenhouse effect is, but it is not what is happening on Venus. Visible light does not reach the surface, or at least plays no role in heating it up. Here is the NASA factsheet. Notice where it says, "Diurnal temperature range: ~0" As in, maximum 464 C, minimum 464 C, average 464 C...I hope I'm finally getting through here. Kauffner ( talk) 14:59, 9 January 2011 (UTC)
I think it is a relevant aspect for the article why the atmosphere of Venus is so much denser than the one on earth. In the German Wikipedia, this question came up, too. Therefore I think it's a good idea to include this aspect in the article. I don't have any sources for these things, neither book nor web. Can anyone help here? Thx. -- Hg6996 ( talk) 09:56, 17 August 2012 (UTC)
In the lead section: "It is currently thought that the atmosphere of Venus up to around 4 billion years ago was more like that of the Earth with liquid water on the surface."
1. There is no citation.
2. The sentence does not make it clear whether or not Venus' atmosphere 4 billion years ago was like Earth's current atmosphere, which has dramatically changed since the dawn of life (see en.wikipedia.org/wiki/Atmosphere_of_Earth#Evolution_of_Earth.27s_atmosphere heading "Evolution of Earth's Atmosphere"), or Earth's atmosphere of 4 billion years ago. For me, this is an interesting discussion because Earth's atmosphere has been fundamentally affected by the processes of life, and if Venus once had an atmosphere like Earth's today, then it is logical to question whether or not life had a role in its origins as well. However, because there is no citation, it is difficult to judge the source of this conjecture.
Perhaps this sentence should be cited or omitted?
fraktol 17:07, 15 May 2010 (UTC)
==
I too would question the above sentence. While there are two citations given (I assume they weren't there originally), they do not really support the statement. The first states "Venus MAY [my emphasis] originally have had oceans IF [my emphasis] its initial water endowment was close to that of Earth". The second states "Perhaps ... Earth had something special happen in the early history that allowed a lot of calcium oxide to come in contact with a lot of carbon dioxide and steadily leech it from the atmosphere. Perhaps the early oceans of Earth allowed this to happen and Venus had NO [my emphasis] comparable early oceans", which if anything, contradicts the statement.
I think I'll change that statement slightly ... Joe. —Preceding unsigned comment added by 202.168.106.124 ( talk) 13:31, 6 November 2010 (UTC)
The original version [3] used vapor and metre. The version around GAN [4] mixed US and UK spelling, so as the current version. What spelling should we use? Materialscientist ( talk) 23:42, 10 January 2012 (UTC)
Since on the surface of Venus, carbon dioxide is a supercritical fluid and not gas, does it mean there are still winds on the surface or are there flows instead? -- Artman40 ( talk) 17:54, 21 May 2013 (UTC)
24.50.151.151 ( talk) 15:32, 17 December 2014 (UTC)
Due to the similarity in pressure and temperature and the fact that breathable air (21% oxygen, 78% nitrogen) is a lifting gas on Venus in the same way that helium is a lifting gas on Earth, the upper atmosphere has been proposed as a location for both exploration and colonization.
If one was to expand this would it be correct to say that a 'water veil" exists 25 miles above the surface of Venus?
A request was made for a new infobox, but can't find one suitable. Any suggestions? FriarTuck1981 ( talk) 01:55, 27 April 2015 (UTC)
Has no one noticed that a table claims the temperature here to be 75°C, while the graph sitting at the top says it's roughly 0°C? Which is more accurate, the graph or the table? — Preceding unsigned comment added by 210.246.56.116 ( talk) 09:53, 30 August 2015 (UTC)
looks like we can finally say Venus has a climate now. Serendi pod ous 19:53, 18 July 2016 (UTC)
I check pages listed in Category:Pages with incorrect ref formatting to try to fix reference errors. One of the things I do is look for content for orphaned references in the wiki linked articles. I have found content for some of Atmosphere of Venus's orphans, the problem is that I found more than one version. I can't determine which (if any) is correct for this article, so I am asking for a sentient editor to look it over and copy the correct ref content into this article.
Reference named "Russell, Philips":
I apologize if any of the above are effectively identical; I am just a simple computer program, so I can't determine whether minor differences are significant or not. AnomieBOT ⚡ 18:47, 8 September 2016 (UTC)
The temperature of this layer—230 K (−43 °C) is far higher than the typical temperature found in the nightside thermosphere—100 K (−173 °C).[2] Kelvin cant be negative. it starts at absolute zero — Preceding unsigned comment added by Xirtyan ( talk • contribs) 18:44, 23 November 2018 (UTC)
I noticed there are four pieces of info that have {{Citation needed}} on the page. These need to be fixed. Firestar464 ( talk) 03:20, 15 September 2020 (UTC)
Most of the linked article is just so much sci-fi claptrap - "floating cities" and so on. I don't care what physicist off his nut wrote a paper that someone considers a RS - there won't be thousands of human beings living in the atmosphere of Venus. I suggest removing that part from the lede as far too fanciful. It's not a matter of technology, either. There has to be a point to colonization, and convincing a vast amount of people to give up Earth for some hang-on-by-your-nails environment is just pure dreaming. This should be a serious article. 50.111.19.2 ( talk) 14:38, 15 September 2020 (UTC)
The detection of phosphine in the atmosphere of Venus is an important discovery and should be mentioned briefly in the lede. When the head of NASA says so, then you know it is likely to be so. Additionally, as can be seen from the ways that the team has tried to eliminate signal-processing issues and used observations from multiple telescopes (i.e., JCMT and ALMA), it is not the case that this detection has not be confirmed - just as with any scientific result, it could be confirmed further, but it is not the case that it has not been confirmed at all. FOARP ( talk) 14:10, 18 September 2020 (UTC)
This article was the subject of a Wiki Education Foundation-supported course assignment, between 18 January 2022 and 9 May 2022. Further details are available
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The table of pressure by altitude uses an imaginary unit of measurement the "atm" for pressure. This unit is not used in SI Metric, and since all of the other units in the table are SI metric it is therefore ambiguous to what "atm" refers. The SI metric unit of pressure is the Pascal.
"in 1982, the International Union of Pure and Applied Chemistry recommended that for the purposes of specifying the physical properties of substances, standard pressure should be precisely 100 kPa (1 bar)." This means that it is ambiguous what the author of the original table quoted in this article intended.
Unless someone can clarify exactly which definition of "atm" was intended by the original author, I intend to change the heading to read "bar". Jamescobban ( talk) 00:31, 5 February 2024 (UTC)
It's common knowledge among people who know what they're talking about that Venus' lack of internal magnetic field allowed most of the gases lighter than carbon dioxide to be stripped away by the solar wind and that's what caused the extreme greenhouse effect and dense atmosphere. The blurb in the intro section should probably mention that instead of the less meaningful but more relevant to Earthling politics...thing that is currently there. I literally hear people say that anthropogenic climate change is going to turn Earth into Venus because of out-of-context statements like that. Octaazacubane ( talk) 04:53, 29 February 2024 (UTC)
For the mixture ratios given in percent or p.p.m., it is not written whether they are by volume, by mass, or maybe by molecules (which would by approximately similar as by volume if the gases are approximately regarded as ideal, but which seems a bit odd regarding the extreme conditions there, where carbon dioxide is probably far from being an ideal gas). Checking reference 2 for answering this question to myself, it was also not easy to find out: only the captions of figures 3 and 4 there mention explicitly the term "volume mixing ratio". Is it that obvious (and not known only to me) what these ratios mean, such that it's not necessary to write it out? Or should it be added for the sake of clarity, because even if known to experts, Wikipedia should be precisely understandable also for non-experts? The main article about the planet Venus mentions at least in the summary box "composition by volume". 213.220.159.151 ( talk) 03:59, 14 March 2024 (UTC)
![]() | Atmosphere of Venus has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it. | |||||||||
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![]() | A fact from this article appeared on Wikipedia's
Main Page in the "
Did you know?" column on
August 16, 2006. The text of the entry was: Did you know ...that just over 50 kilometres above its surface, the
atmosphere of Venus has very similar
pressure and
temperature as does
Earth, making it the most
Earth-like area in the
solar system? |
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I made some minor changes to references; I also deleted a sentence that mentioned the albedo of Venus is 0.76 since one sentence later stated that Venus reflected 90% of the incident sunlight. The alternative to deleting this sentence would have been a long discussion of the different types of albedo (which varies with wavelength), which would have been rather off-topic; people actually interested in albedo can look at the albedo entry.
Geoffrey.landis 15:13, 12 September 2006 (UTC)Geoff Landis
"Hydrogen is primarily present as sulfuric acid (H2SO4), and hydrogen can easily be extracted through condensing the droplets."
Sulfuric acid does not release any hydrogen by "condensing" the droplets. On the contrary, sulfuric acid attracts and holds any water violently. Perhaps this is the reason why there is any trace of water on Venus left at all. 84.160.239.47 22:17, 17 November 2006 (UTC)
The article has several apparent contradictions that need to be explained in footnotes if not the main text ie "sulfur dioxide is 150 parts per million." No mention of sulfur trioxide which should be in surplus if there is "no water." It says 6 parts per million of water vapor in another part of the article. I suppose the problem is the composition of Earth's atmosphere is typically given as gas-only and particulates such as dust, sulphuric acid, ice, and water droplets are discussed separately. Also, Earth atmosphere scientists typically include the carbon dioxide vapor percentage, but not the water vapor percentage; just the opposite of how we have figured Venus, perhaps because the lower atmosphere of Venus is hot enough that carbon dioxide is a gas, not a vapor, as it is in Earth's atmosphere. Neil
The text includes the conjecture that Venus' atmosphere is composed of largely carbon-dioxide and nitrogen mixture because of the lack of a strong magnetic field, lighter gases not being held because of the lack of a strong magnetic field as Earth has. That would hold true also for Mars, which has a larger carbon dioxide-nitrogen atmosphere (if much thinner).
A simpler explanation exists: Venus is hot. Magnetic fields do not hold gases so effectively as does gravity. The Earth has high enough gravitation and cooler temperatures to hold gases as light as methane, ammonia, and water vapor. To be sure, the Earth's atmosphere holds little methane or ammonia because of thermodynamic instability in an oxygen-rich environment, but it holds water vapor very well. It's, of course, gravitation. A strong magnetic field may prevent some chemical reactions in the Earth's upper atmosphere, preventing the formation of such substances like sulfuric acid, but that is a different topic.
Venus is much hotter at its surface, hot enough that with gravity slighter (but not by much!) than the Earth's, Venus cannot hold gases as light as methane, ammonia, and water vapor. Much chillier than Earth, but with far lesser gravity, Mars likewise cannot hold water vapor. With their combinations of temperature and gravitation, both Mars and Venus can hold atmospheres consisting largely of carbon dioxide and nitrogen. -- Paul from Michigan 01:49, 25 November 2006 (UTC)
Life is of course a non-equilibrium state. Under equilibrium, water would react with carbon and carbon compounds to form carbon dioxide, and with sulfur and sulfur compounds to form sulfuric acid. As is well-known one can place carbon and sulfur in cold water and have no reactions.
Biochemistry itself suggests that life formed on Earth from a mixture of substances, some of which would not exist long in an oxygen-rich environment. Of course, water, carbon oxides (whether carbon monoxide or carbon dioxide), and phosphates exist. But most biochemical substances are methane derivatives. Ammonia and hydrogen sulfide would have to have existed.
Living things (plants) can synthesize methane derivatives from carbon dioxide and water and can transform nitrites and nitrates into ammonia. Some bacteria 'fix' nitrogen. But that is life at work.
Most predictions of the future of the Earth suggest that as the sun becomes more luminous, that unless the Earth's orbit becomes adequately displaced from where it is now (I believe that if humanity or some intelligent successor is around, that creature is likely to force the Earth into orbit progressively more distant from the sun as needed), the Earth will get hotter. The Earth is toward the warm end of the life zone, and when the normal temperature on Earth approaches 45C, life will be in big trouble. Much of the biomass will die and become fuel for spectacular forest and brush fires that will thrust more carbon dioxide into the atmosphere, accelerating global warming. Higher evaporation of water will have added another greenhouse gas -- water vapor -- into the atmosphere. Atom for atom, water vapor is an even more powerful greenhouse gas.
Around 70C, the 'wet greenhouse' effect that some say occurred early on Venus takes off, and the Earth's atmosphere itself takes on the characteristics of a pressure cooker. Meanwhile, the greater pressure of the atmosphere causes the atmospheric temperature to rise in accordance with the gas laws. The process accelerates as more of the waters of the sea evaporate into the atmosphere. Some water vapor goes to the upper atmosphere and some water molecules dissociate into oxygen and hydrogen, hydrogen going off into space. Until the seas are evaporated away, there's more water vapor available to replace the water dissociated into oxygen and water.
At 305 C, the critical temperature of the water, liquid water no longer exists. By then, even if the Earth has gigantic clouds protecting the planet from sunlight, pressure alone creates hothouse conditions. (Venus is hot because of the pressure of its atmosphere -- not because of the intense sunlight that shines upon cloud layers that insulate the planet). Carbonate rocks decompose, releasing carbon dioxide, and pressures lead to temperatures high enough to melt surface rocks.
Gory, isn't it? The earth's atmosphere would be full of oxygen from dissociated water, carbon dioxide first from the burning of biomass and petroleum, and then especially the release of it from carbonate rocks, sulfuric acid from the burning of sulfur and sulfur compounds, a little nitrogen, and some water vapor. The Earth could get even hotter than Venus is today -- hot enough to melt all rock surfaces. That's all long before the Sun flares off the atmosphere and beats down upon the exposed surface of the Earth.
That all depends upon the extinction of complex life. We might not have the means -- yet -- of altering the Earth's orbit. But humanity or whatever its successor at the time (advanced pigs?) will likely cherish life enough to get the Hell out of an infernal prospect. The Gaia effect got little chance on Venus or Mars. It may need some help a few hundred million years hence just to continue. Sure, this is speculation, and as such 'original research'... probably forgivable in a talk page. -- Paul from Michigan 10:20, 14 January 2007 (UTC)
The magnetic field doesn't hold in hydrogen, it shields a planet from the solar wind that would slowly scrub the hydrogen away into space. To address your question about sulfur trioxide, I believe the UV-initiated reaction in the upper atmosphere is CO2 + SO2 -> CO + SO3. And then SO3 + H20 -> H2SO4. So there is not an excess of SO3, it recombines with carbon monoxide given the chance. DonPMitchell ( talk) 03:55, 9 August 2008 (UTC)
I agree the clouds might cause most of the greenhouse effect, since they cause the radiating surface to be at a high altitude. Adiabatic compression can then heat the atmosphere below with the very high surface pressure. I've yet to find this in any journal articles, though I have seen this in a presentation by Ned Nikolov that is online. The CO2 might cause an addition 100C or so if we make the approximation of extrapolating the logarithmic dependence we see on Earth. — Preceding unsigned comment added by 2601:281:8200:98AA:C8F2:7A2B:D7AC:466D ( talk) 02:29, 19 February 2019 (UTC)
How much hotter is Venus than Earth?
It's a lot hotter if you compare surface temperatures to surface temperatures -- 288K to 750K. But, if you compare atmospheric temperatures at the same pressures, say at 1 Bar, the difference is a lot less dramatic. Earth's 1 Bar temperature is 288K while Venus' is 360K. If you also subtract out the extra temperature due to Venus having to shed more heat from solar radiation, the difference in atmospheric temperature is around 20 K -- a whole lot less than the almost 500-degree difference in surface temperatures.
This means that the extra heat at the surface is coming from adiabatic compression (extra pressure), not from extrasolar radiation or the greenhouse effect. I've written up an article explaining this more fully and posted it at
www.whiteworld.com/technoland/stories-nonfic/2008-stories/Venus-temp.htm
I'd like to get an external link reference put in this article if I could.
Cyreenik 15:31, 12 April 2007 (UTC)
Cyreenik: A link to your "article" would constitute Original Research. In any case, it's well documented that the extreme surface temperatures on the surface of Venus are due primarily to the huge amount of carbon dioxide, a greenhouse gas, in Venus's atmosphere, in other words, to global warming. "Atmosphere temperature" is--obviously--largely beside the point. TheScotch ( talk) 22:42, 20 December 2017 (UTC)
WP:Good article usage is a survey of the language and style of Wikipedia editors in articles being reviewed for Good article nomination. It will help make the experience of writing Good Articles as non-threatening and satisfying as possible if all the participating editors would take a moment to answer a few questions for us, in this section, please. The survey will end on April 30.
At any point during this review, let us know if we recommend any edits, including markup, punctuation, and language, that you feel don't fit with your writing style. Thanks for your time. - Dan Dank55 ( talk) 21:05, 11 April 2008 (UTC)
I've signed up to review this, and I'll put comments when I get a chance for a thorough read Jimfbleak ( talk) 11:05, 29 April 2008 (UTC)
Jimfbleak ( talk) 16:05, 29 April 2008 (UTC)
Nice article and a good read Jimfbleak ( talk) 09:56, 30 April 2008 (UTC)
From this image I thought Venus' surface level is below Earth's ocean level at 50 meters below. Venus has 3 levels of cloud layers, and the haze lies between each cloud layer. Do someone want to clarify this image a little bit.-- Freewayguy What's up? 20:15, 29 August 2008 (UTC)
I am not an astronomer or physicist, so I may sound idiotic, but shouldn't it be specified whether the elemental composition given in the table is molar or by mass? After all, if in one kilogramme of the Venerian atmosphere there is 965 g of carbon dioxide, this is not the same as saying that in one mol of Venerian atmosphere molecules, 96.5% will be carbon dioxide molecules.
Edit (different person): hyper physics has CO2 in the Venusian atmosphere at 96.5% by volume. I don't know how sources are qualified on Wikipedia (I don't edit, myself), but the values are the same. Could be a good lead on a better citation.
http://hyperphysics.phy-astr.gsu.edu/hbase/Solar/venusenv.html — Preceding unsigned comment added by 130.184.252.75 ( talk) 19:47, 8 June 2019 (UTC)
Particularly, the section referencing carbonyl sulfide... if you reference http://en.wikipedia.org/wiki/Carbonyl_sulfide, it appears this molecule is created from geothermal vents and volcanoes, and readily forms in the presence of CO and S, not a likely candidate to say that it's an "unambiguous indicator of life"
Thoughts? —Preceding unsigned comment added by 66.104.60.6 ( talk) 15:49, 17 August 2009 (UTC)
Today I unsuccessfully attempted to edit this page so that the surface temperature would be in both Fahrenheit and Celsius, rather than just Celsius and Kelvin. Temperatures are supposed to provide a reference point. All articles on Wikipedia are supposed to be written for a general readership, not specifically for scientists. Most Americans aren't familiar with Celsius, and Kelvin is something restricted to scientific use. My suggestion was to list in F and C and then put K over in the information panel because Wikipedia isn't a scientific journal. Someone in the page edit history argued that it isn't necessary to add Fahrenheit for temperature greater than boiling water. That doesn't make any sense. 250 degrees K is cold. But most Americans upon seeing that number would probably think it meant "hot." Sadly, most Americans also couldn't tell you where water boils and freezes on the Celsius scale, and the scales also differ in sensitivity. For example, there are only 100 degrees between the boiling point and freezing point of water on the Celsius scale, but there's a 180-degree span on the Fahrenheit scale. For millions of ordinary people in the U.S., then, these numbers are rather meaningless unless they find a way to convert them to the scale they're used to.
Encyclopedias are for general reference, even the scientific articles. And the standard for a general reference in the U.S. is to list in both Fahrenheit and Celsius. For example, see what Encyclopedia Britannica does here. Also, see how NASA displays it for a general audience [www.nasa.gov/worldbook/venus_worldbook.html here]. Danrz ( talk) 18:37, 4 December 2009 (UTC)
I don't agree with what you think the policy is as it applies here. I know what the convention is and I just showed you what NASA and Encyclopedia Britannica do in the above links for a general readership. And I never said Kelvin shouldn't be on the page. I wanted all three, with Kelvin in the side panel. That's how it is on the Mars page, and Mercury. And scientists will even talk about it in Fahrenheit when speaking to general U.S. readers so that the readers know what s/he is talking about -- e.g. see here and U.S. science magazines that aren't targeted to scientists also list the temperature in Fahrenheit -- see here. Danrz ( talk) 20:39, 4 December 2009 (UTC)
So your most recent argument(after making others in the edit history) is that the USA is eccentric and that it doesn't merit putting the degrees Fahrenheit in parentheses. And in your most recent edit, you hyperlinked the "K", sending all the readers who have no idea what the number really means over to the Wikipedia Kelvin page where there's a formula that they can use to convert it to Fahrenheit -- instead of just putting the Fahrenheit in the article itself. I don't consider that helpful. Danrz ( talk) 20:39, 4 December 2009 (UTC)
Didn't you all know the netric system is a commie plot? — Preceding unsigned comment added by 162.192.181.76 ( talk) 04:45, 18 October 2013 (UTC)
Can someone explain how the hell Venus is supposed to have an atmosphere 100 times heavier than that of the Earth, while Venusian surface gravity is 90% of the Earth's? Either the force of gravity on Venus is much, much stronger or is composed of molecules with a mass, which is not indicative of a gas, but rather of a solid. I will do the exact math later. 62.33.188.17 ( talk) 00:22, 25 December 2009 (UTC)
Thus, the atmospheric pressure at the surface level of Venus should be no more or less than that of Earth's. 62.33.188.17 ( talk) 15:33, 25 December 2009 (UTC)
To answer the original question, Venus has a lot of outgassing due to volcanism. The resulting high temperature and atmospheric pressure prevent CO2 from being fixed into carbonate rocks the way it is on Earth. Of course, that still leaves us with a mystery as to the original cause: Why did Venus have such a freakishly large amount of volcanism, at least in the recent past? This appears to relate to the lack of plate tectonics, which leaves volcanoes the only mechanism to relieve heat or pressure in the interior. Kauffner ( talk) 13:22, 7 January 2011 (UTC)
The figure of 33 C for the terrestrial greenhouse effect is given all over, by almost everyone who discusses this issue. ("Without this effect, the earth would be about 33 C colder than at present." [2]. See also the greenhouse effect article, which cites the IPCC on this.) As for the rest of the sun's heating effect, sunlight is absorbed by the surface and warms it. This heat is transferred to the gas in contact with the surface, both greenhouse, and non-greenhouse. Then the atmosphere is warmed by convection. This allows heat to be retained through the night, etc. Why Venus is so hot is one of the outstanding mysteries of science, so I obviously can't give you a fully satisfactory answer. Significant heat must come from the interior, from volcanism and tectonics. On Earth, the Cretaceous was outstanding for its volcanism, with a superplume in the South Pacific and massive sea-floor spreading, and was also far warmer than today. At Venusian pressures, CO2 has quite different properties than it does on Earth. Less than 30 cm will absorb IR entirely, so there is an insulating effect. Kauffner ( talk) 04:03, 8 January 2011 (UTC)
Ruslik_Zero: Thanks for the link to the Science article abstract. What they meant is certainly clearer there than in the news article. You could dial down the snark, though, since just a little while back you were asking basic physics questions like how convection could heat.
Kauffner ( talk) 04:53, 9 January 2011 (UTC)
The lapse rate is an empirically derived description of the temperature pattern, not an explanation for it. Yes, I know what the greenhouse effect is, but it is not what is happening on Venus. Visible light does not reach the surface, or at least plays no role in heating it up. Here is the NASA factsheet. Notice where it says, "Diurnal temperature range: ~0" As in, maximum 464 C, minimum 464 C, average 464 C...I hope I'm finally getting through here. Kauffner ( talk) 14:59, 9 January 2011 (UTC)
I think it is a relevant aspect for the article why the atmosphere of Venus is so much denser than the one on earth. In the German Wikipedia, this question came up, too. Therefore I think it's a good idea to include this aspect in the article. I don't have any sources for these things, neither book nor web. Can anyone help here? Thx. -- Hg6996 ( talk) 09:56, 17 August 2012 (UTC)
In the lead section: "It is currently thought that the atmosphere of Venus up to around 4 billion years ago was more like that of the Earth with liquid water on the surface."
1. There is no citation.
2. The sentence does not make it clear whether or not Venus' atmosphere 4 billion years ago was like Earth's current atmosphere, which has dramatically changed since the dawn of life (see en.wikipedia.org/wiki/Atmosphere_of_Earth#Evolution_of_Earth.27s_atmosphere heading "Evolution of Earth's Atmosphere"), or Earth's atmosphere of 4 billion years ago. For me, this is an interesting discussion because Earth's atmosphere has been fundamentally affected by the processes of life, and if Venus once had an atmosphere like Earth's today, then it is logical to question whether or not life had a role in its origins as well. However, because there is no citation, it is difficult to judge the source of this conjecture.
Perhaps this sentence should be cited or omitted?
fraktol 17:07, 15 May 2010 (UTC)
==
I too would question the above sentence. While there are two citations given (I assume they weren't there originally), they do not really support the statement. The first states "Venus MAY [my emphasis] originally have had oceans IF [my emphasis] its initial water endowment was close to that of Earth". The second states "Perhaps ... Earth had something special happen in the early history that allowed a lot of calcium oxide to come in contact with a lot of carbon dioxide and steadily leech it from the atmosphere. Perhaps the early oceans of Earth allowed this to happen and Venus had NO [my emphasis] comparable early oceans", which if anything, contradicts the statement.
I think I'll change that statement slightly ... Joe. —Preceding unsigned comment added by 202.168.106.124 ( talk) 13:31, 6 November 2010 (UTC)
The original version [3] used vapor and metre. The version around GAN [4] mixed US and UK spelling, so as the current version. What spelling should we use? Materialscientist ( talk) 23:42, 10 January 2012 (UTC)
Since on the surface of Venus, carbon dioxide is a supercritical fluid and not gas, does it mean there are still winds on the surface or are there flows instead? -- Artman40 ( talk) 17:54, 21 May 2013 (UTC)
24.50.151.151 ( talk) 15:32, 17 December 2014 (UTC)
Due to the similarity in pressure and temperature and the fact that breathable air (21% oxygen, 78% nitrogen) is a lifting gas on Venus in the same way that helium is a lifting gas on Earth, the upper atmosphere has been proposed as a location for both exploration and colonization.
If one was to expand this would it be correct to say that a 'water veil" exists 25 miles above the surface of Venus?
A request was made for a new infobox, but can't find one suitable. Any suggestions? FriarTuck1981 ( talk) 01:55, 27 April 2015 (UTC)
Has no one noticed that a table claims the temperature here to be 75°C, while the graph sitting at the top says it's roughly 0°C? Which is more accurate, the graph or the table? — Preceding unsigned comment added by 210.246.56.116 ( talk) 09:53, 30 August 2015 (UTC)
looks like we can finally say Venus has a climate now. Serendi pod ous 19:53, 18 July 2016 (UTC)
I check pages listed in Category:Pages with incorrect ref formatting to try to fix reference errors. One of the things I do is look for content for orphaned references in the wiki linked articles. I have found content for some of Atmosphere of Venus's orphans, the problem is that I found more than one version. I can't determine which (if any) is correct for this article, so I am asking for a sentient editor to look it over and copy the correct ref content into this article.
Reference named "Russell, Philips":
I apologize if any of the above are effectively identical; I am just a simple computer program, so I can't determine whether minor differences are significant or not. AnomieBOT ⚡ 18:47, 8 September 2016 (UTC)
The temperature of this layer—230 K (−43 °C) is far higher than the typical temperature found in the nightside thermosphere—100 K (−173 °C).[2] Kelvin cant be negative. it starts at absolute zero — Preceding unsigned comment added by Xirtyan ( talk • contribs) 18:44, 23 November 2018 (UTC)
I noticed there are four pieces of info that have {{Citation needed}} on the page. These need to be fixed. Firestar464 ( talk) 03:20, 15 September 2020 (UTC)
Most of the linked article is just so much sci-fi claptrap - "floating cities" and so on. I don't care what physicist off his nut wrote a paper that someone considers a RS - there won't be thousands of human beings living in the atmosphere of Venus. I suggest removing that part from the lede as far too fanciful. It's not a matter of technology, either. There has to be a point to colonization, and convincing a vast amount of people to give up Earth for some hang-on-by-your-nails environment is just pure dreaming. This should be a serious article. 50.111.19.2 ( talk) 14:38, 15 September 2020 (UTC)
The detection of phosphine in the atmosphere of Venus is an important discovery and should be mentioned briefly in the lede. When the head of NASA says so, then you know it is likely to be so. Additionally, as can be seen from the ways that the team has tried to eliminate signal-processing issues and used observations from multiple telescopes (i.e., JCMT and ALMA), it is not the case that this detection has not be confirmed - just as with any scientific result, it could be confirmed further, but it is not the case that it has not been confirmed at all. FOARP ( talk) 14:10, 18 September 2020 (UTC)
This article was the subject of a Wiki Education Foundation-supported course assignment, between 18 January 2022 and 9 May 2022. Further details are available
on the course page. Student editor(s):
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article contribs).
The table of pressure by altitude uses an imaginary unit of measurement the "atm" for pressure. This unit is not used in SI Metric, and since all of the other units in the table are SI metric it is therefore ambiguous to what "atm" refers. The SI metric unit of pressure is the Pascal.
"in 1982, the International Union of Pure and Applied Chemistry recommended that for the purposes of specifying the physical properties of substances, standard pressure should be precisely 100 kPa (1 bar)." This means that it is ambiguous what the author of the original table quoted in this article intended.
Unless someone can clarify exactly which definition of "atm" was intended by the original author, I intend to change the heading to read "bar". Jamescobban ( talk) 00:31, 5 February 2024 (UTC)
It's common knowledge among people who know what they're talking about that Venus' lack of internal magnetic field allowed most of the gases lighter than carbon dioxide to be stripped away by the solar wind and that's what caused the extreme greenhouse effect and dense atmosphere. The blurb in the intro section should probably mention that instead of the less meaningful but more relevant to Earthling politics...thing that is currently there. I literally hear people say that anthropogenic climate change is going to turn Earth into Venus because of out-of-context statements like that. Octaazacubane ( talk) 04:53, 29 February 2024 (UTC)
For the mixture ratios given in percent or p.p.m., it is not written whether they are by volume, by mass, or maybe by molecules (which would by approximately similar as by volume if the gases are approximately regarded as ideal, but which seems a bit odd regarding the extreme conditions there, where carbon dioxide is probably far from being an ideal gas). Checking reference 2 for answering this question to myself, it was also not easy to find out: only the captions of figures 3 and 4 there mention explicitly the term "volume mixing ratio". Is it that obvious (and not known only to me) what these ratios mean, such that it's not necessary to write it out? Or should it be added for the sake of clarity, because even if known to experts, Wikipedia should be precisely understandable also for non-experts? The main article about the planet Venus mentions at least in the summary box "composition by volume". 213.220.159.151 ( talk) 03:59, 14 March 2024 (UTC)