The Pre-Biotic Atmosphere
- The atmosphere of early Earth bore little resemblance to the oxygen-rich air we breathe today.
- Geological evidence suggests that free oxygen was nearly absent.
- Instead, the atmosphere likely consisted of gases such as methane (CH₄), carbon dioxide (CO₂), ammonia (NH₃), and water vapor (H₂O), released through intense volcanic activity and constant meteorite bombardment.
Instead, the atmosphere likely consisted of gases such as methane ($CH_4$), carbon dioxide ($CO_2$), ammonia ($NH_3$), and water vapor ($H_2O$), released through intense volcanic activity and constant meteorite bombardment.
Key Atmospheric Factors
- Lack of Free Oxygen (O₂):
- Without free oxygen, organic molecules were not degraded by oxidation.
- This allowed their accumulation and further chemical reactions.
- No Ozone Layer:
- The absence of an ozone layer (O₃) exposed the surface to intense UV radiation.
- This radiation provided energy for the formation of organic molecules.
