The atmosphere of the Archean eon—one-third of Earth's history—is important for
understanding the evolution of our planet and Earth-like exoplanets. New geological proxies …

In the coming years and decades, advanced space-and ground-based observatories will
allow an unprecedented opportunity to probe the atmospheres and surfaces of potentially …

Photosystem II is the water-oxidizing and O2-evolving enzyme of photosynthesis. How and
when this remarkable enzyme arose are fundamental questions in the history of life that …

Methane has been proposed as an exoplanet biosignature. Imminent observations with the
James Webb Space Telescope may enable methane detections on potentially habitable …

The rate of primary productivity is a keystone variable in driving biogeochemical cycles
today and has been throughout Earth's past. 1 For example, it plays a critical role in …

The rapid increase of carbon dioxide concentration in Earth's modern atmosphere is a
matter of major concern. But for the atmosphere of roughly two-and-half billion years ago …

Although pH is a fundamental property of Earth's oceans, critical to our understanding of
seawater biogeochemistry, its long-timescale geologic history is poorly constrained. We …

Abstract The James Webb Space Telescope (JWST) recently measured the transmission
spectrum of K2-18b, a habitable-zone sub-Neptune exoplanet, detecting CH 4 and CO 2 in …

Recognizing whether a planet can support life is a primary goal of future exoplanet spectral
characterization missions, but past research on habitability assessment has largely ignored …

The origin of oxygenic photosynthesis was the most important metabolic innovation in Earth
history. It allowed life to generate energy and reducing power directly from sunlight and …