Planetary Science Institute study pinpoints when early Earth became ready for life

New research published in Nature Communications suggests that Earth may have developed the stable conditions necessary for the chemistry of life approximately 4.33 billion years ago. Using a three-dimensional computer model, scientists led by Oleg Abramov of the Planetary Science Institute reconstructed the heating effects of asteroid, comet, and planetesimal impacts on Earth’s crust between 4.5 and 3.5 billion years ago.

Prior to 4.4 billion years ago, frequent global sterilization events caused by heavy bombardment created an inhospitable environment. However, as impacts became less disruptive, portions of the shallow crust cooled and remained stable. By 4.25 billion years ago, these stable regions accounted for more than half of the crustal volume in the model.

The study specifically examined the potential for an ‘RNA world,’ a proposed stage in biological history where RNA molecules could carry information and facilitate chemical reactions before the emergence of DNA. While large impacts could destroy fragile molecules through heat, the researchers noted that collisions also helped create hydrothermal systems, providing the water, warmth, and chemical energy essential for life’s precursors.