Research says Mars had oxygen-rich atmosphere

[stephen63]

Differences between Martian meteorites and rocks examined by a NASA rover can be explained if Mars had an oxygen-rich atmosphere 4000 million years ago—well before the rise of atmospheric oxygen on Earth 2500 million years ago.
As oxidation is what gives Mars its distinctive colour it is likely that the 'red planet' was wet, warm and rusty billions of years before Earth's atmosphere became oxygen rich.

Read more at: http://phys.org/news/2013-06-mars-oxyge ... s.html#jCp

[Ann]

That's really interesting. Personally I often call Mars "the rusty planet", and in order to have rust, you should have oxygen. So I should not be surprised that Mars had an oxygen-rich atmosphere a long time ago to make all that rust.

I'm still puzzled, though. Earth's oxygen-rich atmosphere has been made by biological processes, and the Earth's atmospheric oxygen is "free oxygen", unbound to other elements. Oxygen is highly reactive and has to be replenished all the time. I can see that the atmospheric oxygen of Mars may have lasted only a short time and so wasn't strongly replenished, but why was it "free", unbound to other elements, so that it could react with Martian minerals in the first place? Or maybe that's not how it works. I guess not.

Ann

[stephen63]

That's really interesting. Personally I often call Mars "the rusty planet", and in order to have rust, you should have oxygen. So I should not be surprised that Mars had an oxygen-rich atmosphere a long time ago to make all that rust.

I'm still puzzled, though. Earth's oxygen-rich atmosphere has been made by biological processes, and the Earth's atmospheric oxygen is "free oxygen", unbound to other elements. Oxygen is highly reactive and has to be replenished all the time. I can see that the atmospheric oxygen of Mars may have lasted only a short time and so wasn't strongly replenished, but why was it "free", unbound to other elements, so that it could react with Martian minerals in the first place? Or maybe that's not how it works. I guess not.

Ann

I wondered the same thing. How did the oxygen get there and was it part of a biological process.

[Chris Peterson]

That's really interesting. Personally I often call Mars "the rusty planet", and in order to have rust, you should have oxygen. So I should not be surprised that Mars had an oxygen-rich atmosphere a long time ago to make all that rust.

I'm still puzzled, though. Earth's oxygen-rich atmosphere has been made by biological processes, and the Earth's atmospheric oxygen is "free oxygen", unbound to other elements. Oxygen is highly reactive and has to be replenished all the time. I can see that the atmospheric oxygen of Mars may have lasted only a short time and so wasn't strongly replenished, but why was it "free", unbound to other elements, so that it could react with Martian minerals in the first place? Or maybe that's not how it works. I guess not.

Free O₂ from life is one suggestion. But the paper also discusses non-biological chemical reactions such as the breakdown of FeO and MgO that could produce free O₂ in the atmosphere.

[geckzilla]

I'm not sure what bothers me more. The use of thousands of millions rather than billions or the fact that the original Nature paper would run me $32 to find out the details of the matter. I guess I'm not really that interested.

edit: But wait! I somehow completely missed this ReadCube link in the article options. Investigation is forthcoming.

edit2: $4 to "rent" digital version with Read Cube. $8 to buy it. Maybe I'm spoiled by the way science literature works confuses me endlessly.

[bystander]

Rocks suggest Mars had oxygen-rich atmosphere 4000m years ago
University of Oxford | 2013 Jun 20

Volcanism on Mars controlled by early oxidation of the upper mantle - J. Tuff, J. Wade, B. J. Wood

• Nature 498(7454) 342 (20 Jun 2013) DOI: 10.1038/nature12225