Air

Origins of the atmosphere

We do not know much about the origins of the current atmosphere of the Earth nor about that of other planets. It might have formed during the aggregation of the planet or during catastrophic events or even slowly and relentlessly over the geological ages. According to the most recent assumptions, the nitrogen, carbon dioxide and water vapour that are presently contained in the atmosphere must have been generated by volcanic events and chemical reactions that occurred approximately 3.8 billion years ago, when the Earth already had a superficial crust and its temperature was low enough to prevent the gases coming from inside the planet from dispersing into the space. Oxygen is thought to have formed later, both through the decomposition of water vapour, under the effect of electric discharges and solar radiations in the high atmosphere, and by the carbon dioxide contained in the atmosphere through the function of the chlorophyll in the photosynthesis, that began as the first auto-trophic organisms (vegetables species) made their appearance on Earth.