A unique study of ancient diamonds has shown that the basic chemical composition of the Earth’s atmosphere, which makes it habitable, appeared at least 2.7 billion years ago. The volatile gases preserved in diamonds were present there in the same proportions as in the modern mantle. This indicates the absence of fundamental changes in the proportions of volatiles in the atmosphere over the past several billion years. This means that they appeared soon after the formation of the Earth and remained constant for a long time.
“The ratio and composition of volatiles in the atmosphere reflects the composition of volatiles in the mantle. We have no evidence of significant changes since these diamonds were formed 2.7 billion years ago, ”said lead researcher Michael Broadley.
The researchers also explained that volatile substances such as hydrogen, nitrogen, and neon are light chemical elements and compounds that easily evaporate when exposed to heat or pressure changes. Carbon and nitrogen are the most important elements for life. At the same time, not all planets are rich in volatiles – Venus and Mars have lost most of their volatiles during development. Typically, a planet rich in volatiles has a better chance of supporting life, so the search for life on planets is mainly centered around finding these volatiles.
On Earth, volatiles are mainly formed inside the planet and are carried to the surface as a result of volcanic eruptions. Studying when volatiles entered the Earth’s atmosphere is key to understanding when conditions on the planet were suitable for the emergence and development of life.