Mars Had an Oxygen-rich Atmosphere Billions of Years Ago

A couple of potential problems, (maybe)...

1) They are assuming that the surface rocks, (on Mars), that they are analyzing, that are billions of years old, originated there.

2) If Mars had an oxygen rich atmosphere, where did the oxygen go?

" Interpretation of the mineralogy of asteroids is complicated by the effects of space weathering, which tends to redden and darken the surfaces of asteroids."

From here:

http://rimg.geoscienceworld.org/content/68/1/273.abstract

I think it's possible that Mars had a very short lived oxygen event that came in the form of, (oxygen rich), asteroids and meteorites; or by the possibility that the reddening was caused by Mars having no atmosphere at all, and be the result of space weathering.

Space weathering like: Playing in the Oxygen wind?

Nah. Lower gravity. Simply enough lower gravity, to allow happening over billions of years:

Over Eons, first Hydrogen escaped, then Nitrogen and Oxygen. Now, what is left is the heaviest, in 0,01 or so pressure. Still enough, to blow off dust from the martian explorers's solar cells for 5 years.

Master Mark,

did you see this?

There the is the wind of which you talk!

That's pretty cool.

Anyway, I think other things could account for Mars' red color, and it seems a little premature to claim that it once had an oxygen rich atmosphere.

This isn't about Mars, but it's an interesting write up on how scientists jump to conclusions, and then try to work the data to fit.

http://www.holoscience.com/wp/venus-isnt-our-twin/

I am no expert but I saw a show on TV that was quite informative I think it was NOVA or maybe it was a show on H2. I have descent background knowledge making me less gullible than most. At the time it all seemed plausible that is why I think it was NOVA. H2 usually pushes the envelope on what I think is sensible. They have ample evidence to reach the above conclusion. They believe Mars like Earth had a powerful magnetic belt that protected its atmosphere. Somehow it lost that belt. That was very disturbing to who ever uncovered the evidence. We all assume these magnetic belts are permanent even if they switch pole every now and then. Unfortunatly, I can't remember more.

I pretty much agree with the article the OP cited. Earth's great oxygenating event has been interpreted to be much later than any such event on Mars. The presence of oxygen atmosphere does indeed point to phtosynthetic life on Mars in the past, and if so, we should look for the oil and gas to prove it. Interesting thought in that Mars apparently never did have a core similar to that of Earth, and was not protected from the solar breeze stripping away its atmosphere over time, as there was no magnetosphere.