Global Journal of Science Frontier Research, A: Physics and Space Science, Volume 23 Issue 5

Figure 3: Mars with a Paleo-Ocean © 2023 Global Journals 1 Year 2023 34 Global Journal of Science Frontier Research Volume XXIII Issue ersion I VV ( A ) The New Mars Synthesis: Circumstantial Evidence of a Past Persistent Gaia on the Red Planet greenhouse of near Earthly atmospheric pressure, however, studies of such greenhouses, basically with CO 2 and water vapor, as the main greenhouse gases, perhaps assisted by a small methane component, while plausible, are geochemically unstable. This is due to the formation of carbonic acid and its reaction with iron rich phyllosilicate lavas to form ferrous-carbonates and magnesium carbonate along with quartz. This geochemical instability means that the greenhouse could not last long on Mars, but would instead collapse to form massive carbonate deposits. However, the greenhouse regime on Mars was obviously of long duration and only trace amounts of carbonate minerals have been found in Martian atmospheric dust, Bandfield et al. (2003). However, this geochemical instability can be solved by adding a strong free oxygen component to the greenhouse atmosphere either photolytically Fairen et al (2004), or photosynthetically, Brandenburg (2015) Molecular oxygen is presently the 4 th most abundant gas in the Mars atmosphere, following argon in abundance and being twice as abundant as carbon monoxide. Oxygen is very reactive, and breaks down ferrous carbonates into CO 2 and bright red ferric oxide, hematite. The CO 2 is thus displaced by oxygen and recycled back into the atmosphere to maintain the greenhouse. Therefore, for iron rich soils, as found on Mars, McGlynn et al. (2012), (see Figure 4) a CO 2 greenhouse system can be stabilized by a strong oxygen component. Free oxygen in the presence of vulcanism also leads to the formation of sulfuric acid, Fairen (2004) which further reacts with carbonates to release CO 2 and form sulphates. Therefore, a strong and persistent CO 2 greenhouse, leading to long lived liquid water conditions, is possible on Mars, provided a strong molecular oxygen component is also present. The result would be a Mars with abundant, bright red, sedimentary beds formed by standing water, as seen in Fig. 5 at Gale crater. Also sulphates but few carbonates would be seen in the case of an oxygen stabilized CO 2 greenhouse on Mars. The question then becomes, what would be the source of the molecular oxygen that would stabilize this persistent greenhouse? The answer is biology.