New Scientist: Venus' Atmosphere Implies Life

WolfWithoutAClause writes "This New Scientist article says that the atmosphere of Venus has features that may only be explaineable by the existence of life in its upper atmosphere. In particular it has cartain chemicals which are extremely difficult to make inorganically. At the altitude where life is suspected the temperature is about 70C and about 1 atmosphere. There are gases there which are not naturally found together. The article suggests something is actively producing them, quite possibly, life."

Comments

Sulfur compounds and "proof of life"

[hyacinthus]

I found an interesting article which, among other things, discusses the presence of hydrogen sulfide and sulfur dioxide in volcanic gases. The article is on the website of the U. S. Geological Survey and can be found here. A highlight:

An interesting chemical relationship exists between the sulfur dioxide and the hydrogen sulfide released by the volcano. These two gases react quickly (within minutes) with each other to produce sulfur particles and water vapor. Both of the products of this reaction are odorless and are less toxic than either H2S or SO2. Most of the hydrogen sulfide released in eruptive areas on Kilauea is consumed and is converted to sulfur particles by this process, because there is much more sulfur dioxide than hydrogen sulfide coming out of the volcano. This is why you seldom smell hydrogen sulfide at the summit caldera or along the eruptive east rift. The volcano has its own hydrogen sulfide abatement system! Geothermal areas, by contrast, have no large quantities of SO2 available for reaction, so any H2S released is removed by reaction with oxygen in the air to form sulfur dioxide, a process that takes a day or more.

But another sentence in the article implies that nevertheless the two gases can be found together. And certainly neither of them are produced by biological activity in this case.

As for carbonyl sulfide (also "carbon oxysulfide", or COS - essentially carbon dioxide with sulfur substituting for one of the oxygens), I don't know much about how it can be synthesized. I suspect that it is a product of careful hydrolysis of thiophosgene (CSCl2 - itself not an easy thing to make), but this would hardly be occurring naturally. I know that the gas is unstable, susceptible to hydrolysis into carbon dioxide and hydrogen sulfide. This article discusses its presence in our own atmosphere; the bulk of it comes from natural sources.

Incidentally, why do these articles on Slashdot of genuine scientific interest attract more stupid posts than usual? Everyone's trying to crack lame sci-fi jokes, and few are addressing the matter seriously.