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

IV. T he E arly E mergence of L ife on E arth Evidence of photosynthetic cyanobacteria colonies, in form of stromatolites, has now been found in the Eoarchean geologic formations of Greenland dating from 3.7 Ga, Nutman et al. (2016), Similar structures have been found in the Paleoarchean 3.5Ga formations of Strelley Pool in the Pilbara Craton, in Australia, Clarke and Stoker (2013). This early appearance of evidence of biology suggests that the laws of physics favor the emergence of photosynthetic life on Earthlike planets even soon after their formation. In particular warm temperature and abundant liquid water appear most favorable for the appearance of life. V. T he M artian G aia The conditions of warm temperatures and abundant liquid water evident on Early Mars, empirically, would have led to biology as they did on Early Earth. The strong oxygen component in the atmosphere that would have to be present on Mars to stabilize its CO 2 greenhouse, would have been generated photosynthetically, that is, by biology. Photosynthesis, relying primarily on visible wavelengths to which water and oxygen are transparent can become a self-feeding process, uninhibited by its “waste gas” oxygen. the Schuman-Runge bands, Thomas, and Stamnes, (1999.), (see Figure 6) which begin at wavelengths shorter than 242nm, which marks the onset of ozone production. Therefore, UV Photolysis as a method of creating free oxygen is self-limiting. Also, by breaking down water and methane, such hard UV would destroy the two most efficient greenhouse gases in the atmosphere, leading to rapid greenhouse collapse on Mars as it lost its efficiency. © 2023 Global Journals 1 Year 2023 36 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 On Earth, mechanisms for producing oxygen were obviously overwhelmed by various environmental sinks, Kasting et al. (1979), and remained low in the early Earthly record until the GOE (Great Oxygen Event) at approximately at 2.3 Gya . This would include various UV driven photolysis processes, Holland (2006). In the GOE it appears photosynthetic life reached some sort of “critical mass” and oxygen levels grew exponentially. Apparently, after approximately 1.5 billion years of very low oxygen levels Earth experienced then an explosive increase to nearly present levels in roughly 10 million years Luo, G. M. et al. (2016). Therefore, we have seen on Earth that warm, wet conditions appear to foster biology even on young rocky planets, and that once photosynthetic biology becomes established it is capable of explosive growth. Alternatively, models for formation of a photolytically sourced oxygen component, based on the UV breakdown of CO 2 and water, are self-limiting due to the fact that the ultra-violet wavelength bands that power them, are blocked by the same oxygen they generate. Wavelengths shorter than 185nm, are seen in experiments to cause photolysis of water, Bar-Nun, and Hartman (1978)and UV bands shorter than167nm are seen to cause photolysis of CO 2 , Schmidt et al. (2013) , that can lead to free oxygen. However, these same UV bands are then blocked by the strong UV absorption of the same O 2 they create. These UV photolytic wavelengths are absorbed by free oxygen absorption in