From Magma Oceans to Breathable Air

These sources examine the cosmological and biological timeline of Earth’s transformation from a sterile, dry rock into a habitable planet. The narrative details how volatile elements like water and carbon were delivered through early solar system processes and the Theia impact, which eventually allowed for a stable atmosphere and oceans. This geochemical shift enabled the simultaneous rise of oxygen-producing cyanobacteria and anaerobic microbes like Sericytochromatia, which thrived in diverse ecological niches. By aligning geological milestones with microbial evolution, the text illustrates how planetary habitability emerged from a complex patchwork of oxygen-rich and anoxic environments. Ultimately, the sources emphasise that the precise timing of chemical delivery and the resulting redox heterogeneity were the essential catalysts for life's diversification.