Setting the stage: Building and maintaining a habitable world and the early conditions that could favor life's beginnings on Earth and beyond

TL;DR

This paper reviews the early Earth's conditions during the Hadean, exploring planetary formation, surface and atmospheric evolution, prebiotic chemistry scenarios, and the influence of impacts on life's origins.

Contribution

It synthesizes recent perspectives on the Hadean environment, connecting planetary processes with prebiotic chemistry and impact effects to better understand life's emergence.

Findings

Hadean Earth was more clement than previously thought

Impacts played a significant role in shaping early conditions

Multiple prebiotic pathways are plausible under early Earth conditions

Abstract

The Hadean, once thought to be uninhabitable and tumultuous, has more recently been recontextualized as a clement time in which oceans, land, and life likely appeared on Earth. This non-exhaustive chapter follows multiple threads from planet formation to the origin of life. We place significant emphasis on the solar system context for the Earth, the timing and nature of crustal formation and the evolution of the surface and atmosphere. Several scenarios for prebiotic chemistry are also discussed including atmospheric photochemistry, wet-dry and freeze-thaw cycles, and hydrothermal vent systems. We attempt to draw connections between the large-scale, planetary processes and various origin of life pathways to illustrate possible overlaps and correlations. In detail, we conclude with and discuss the "impact of impacts" to show how asteroid and comet impacts during the Hadean may have affected many of these processes and scenarios, from generating land to altering the chemical composition and oxidation state of the early Earth's atmosphere and surface.