1. New Estimates of Earth's Ancient Climate and Ocean pH

    Artist concept of the early Earth. Source: NASA's Goddard Space Flight Center Conceptual Image Lab Image credit: None
    Artist concept of the early Earth. Source: NASA's Goddard Space Flight Center Conceptual Image Lab

    A recent study provides new constraints on the environmental conditions that were present on the ancient Earth. Previous approximations of early Earth’s climate and ocean pH vary dramatically, but the new study aims to provide more accurate estimates. This is important because these conditions could have profoundly influenced the origins and early evolution of life.

    In the study, researchers applied a self-consistent geological carbon cycle model to the last 4 billion years of Earth’s history. The results predict that the climate was temperate, and that the ocean pH was nearly neutral throughout the Precambrian (4.6 billion years ago to roughly 541 million years ago). In fact, the study indicates that life may have emerged and diversified in conditions that could have been similar to those on the Earth today.

    The study, “Constraining the climate and ocean pH of the early Earth with a geological carbon cycle model,” was published in the Proceedings of the National Academy of Sciences (PNAS). The work was supported in part by NASA Astrobiology through the Exobiology Program and the NASA Astrobiology Institute (NAI).

    Source: [Astrobiology at NASA]