A lot of people tend to narrowly focus on only Oxygen, Hydrogen, and carbon when considering the suitability for life. But the organic processes that we rely on require more elements than just those two, one of those often overlooked elements is Nitrogen.

In examining Venus for chemical suitability I noticed it only has like ~ %2 atmospheric Nitrogen concentration (from wiki). Where's all the Nitrogen?

My assumption is that there is a whole lot more trapped in liquid Nitric Acid or other acids or mineral deposits. If that is the case what is the estimated amount contained? If that is not the case, how did Earth end up with all the Nitrogen?

  • 2
    $\begingroup$ Well, Venus' atmosphere is about 50x more dense than Earth's, so the 2% nitrogen there is roughly comparable to Earth's 70% (depending on if your counting moles or kilograms). $\endgroup$
    – uhoh
    Oct 23, 2018 at 13:22
  • $\begingroup$ @anon - From the responses to your question, it sounds like there's more nitrogen in absolute measurements, but a great deal less proportional to other elements. And that's what you're really asking about, correct? $\endgroup$ Oct 23, 2018 at 15:47

1 Answer 1


There is nitrogen in the atmosphere of Venus, four times the amount of nitrogen on Earth. Because Venus' atmosphere is so dense, made up almost entirely of carbon dixode, the percentage of nitrogen is rather small in comparison to Earth's atmosphere, but the nitrogen is there.

Space.com: Venus' Atmosphere: Composition, Climate and Weather

Atmospheric makeup:

The atmosphere of Venus is made up almost completely of carbon dioxide. It also includes small doses of nitrogen and clouds of sulfuric acid. The air of Venus is so dense that by mass, the small traces of nitrogen are four times the amount found on Earth, although nitrogen makes up more than three-fourths of the terrestrial atmosphere. This composition causes a runaway greenhouse effect that heats the planet even hotter than the surface of Mercury, although Venus lies farther from the sun. When the rocky core of Venus formed, it captured much of the gas gravitationally.

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    $\begingroup$ This doesn't answer the question. Sure, there is a lot more atmospheric nitrogen than on Earth, and the percentage is so low due to the sheer amount of carbon dioxide on Venus when in fact it's really dense, but... Still, that doesn't fully explain why the percentage of nitrogen is so low. Restated, why is the percentage of CO2 so high? $\endgroup$
    – matt_rule
    Oct 23, 2018 at 23:18
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    $\begingroup$ @matt_rule The proper question to ask is why Earth's atmosphere has such a low concentration of CO2 and other carbon based compounds compared to other planets. Of course, we know where that missing carbon is - it is bound in sedimentary rocks. If all the limestone like compounds littering the Earth surface were to decompose suddenly, we will end up with exactly the amount of CO2 to make Earth into Venus (such calculations were done before, most recently by Octave Levenspiel). $\endgroup$
    – oakad
    Oct 24, 2018 at 0:38
  • $\begingroup$ @oakad could you expand that into an answer? I think it would nicely complement this one $\endgroup$
    – Bear
    Oct 24, 2018 at 12:41
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    $\begingroup$ @Bear I asked and self answered a similar question some years ago. $\endgroup$
    – oakad
    Oct 25, 2018 at 1:38

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