ETH researches the chemical prerequisites for life

(CONNECT) Researchers at the Centre for Origin and Prevalence of Life at the Swiss Federal Institute of Technology in Zurich (ETH) have investigated the chemical basis for the emergence of life on Earth. According to their findings, an essential prerequisite is the presence of a certain amount of phosphorus and nitrogen, according to a press release.

The team led by Craig Walton and Maria Schünbächler shows that the formation of a planetary nucleus already determines whether these two elements are formed in sufficient quantities. This in turn requires a certain concentration of oxygen. If the oxygen content is too low, the phosphorus combines with heavy metals and sinks into the planet's core. If the oxygen concentration is too high, however, the nitrogen volatilizes in the atmosphere. The researchers found the required amount by studying the Earth's early history: 4.6 billion years ago, the conditions on Earth were exactly right to create the necessary concentrations of phosphorus and nitrogen.

"Our models make it clear that the Earth is exactly in this range. If we had had just a little more or less oxygen during the formation of the Earth's core, there would not have been enough phosphorus and nitrogen for life to form," Craig Walton, first author of the current study, is quoted as saying in the press release. Phosphorus is required for the formation of DNA and RNA, nitrogen for the generation of proteins.

Whether the necessary conditions exist on a planet depends on the composition of the respective central star of a solar system. Only if its chemical composition fulfills the above-mentioned requirements could the conditions for the emergence of life be present on the surrounding planets. The researchers therefore recommend focusing the search for life on solar systems that are similar to our own. The study has been published in the current issue of the journal "Nature Astronomy". ce/ww