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

In contrasts, photosynthesis by wavelengths in the visible range is self-promoting, since it functions in the wavelengths, to which water and oxygen are transparent, rather than the UV which absorbed by free oxygen. Photosynthesis also and creates an ozone layer by its oxygen, which then blocks UV that is harmful to plants, allowing plant life to spread from the water to the land. Photosynthesis, then done by biology would overwhelm abiotic photolysis on Mars, as it obviously did on Earth. That life would create an environment that would be conducive to yet more life, is in keeping with the Gaia principle, Lovelock and Margulis (1974, which is seen operating on Earth. Thus, a Martian Gaia would promote oxygen and by this stabilize the same atmospheric greenhouse which allow more oxygen to be produced. Accordingly, the existence and duration of the liquid water epoch on Mars can be ascribed to biology as part of a Martian Gaia. VI. T he F all of M ars Sadly, life is not only very effective in in creating conditions favorable to more life, but it is also fragile. Earth has experienced several major mass extinction events, some of them from known causes, like the Chixulube impact, and others like the great Permian extinction, which was much more severe and also much more mysterious. Some massive mass extinction event afflicted Mars in recent geologic time, and this apparently destroyed that planet’s ability to sustain a large biosphere. However, life is also tenacious and adaptable, and consistent with the Mars Gaia hypothesis, there exists evidence from Mars rover measurements that a residual biosphere, producing both oxygen and methane in the spring and summer on northern Mars, is still operating, Trainer, et al. (2019). (see Figure 7). 1 Year 2023 37 Frontier Research Volume XXIII Issue ersion I VV ( A ) Science © 2023 Global Journals Global Journal of The New Mars Synthesis: Circumstantial Evidence of a Past Persistent Gaia on the Red Planet Figure 6: The UV absorption cross section of oxygen with the approximate ranges of UV causing photolysis of water vapor and CO 2 processes thought to create free molecular oxygen abiotically. Graph adapted from with additional data from Thomas, and Stamnes, (1999), with CO 2 and H 2 O data from Venot, O. et al. (2018) and Warren, S. G., and R. E. Brandt (2008), respectively. As can be seen, absorption of UV by O 2 created by photolysis blocks the same UV bands that could create more of it from CO 2 and H 2 O photolysis, choking off the process.