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 …

We review the origin and evolution of the atmospheres of Earth, Venus and Mars from the
time when their accreting bodies were released from the protoplanetary disk a few million …

Earth has had oceans for nearly four billion years and Mars had lakes and rivers 3.5–3.8
billion years ago. However, it is still unknown whether water has ever condensed on the …

One popular view of Venus' climate history describes a world that has spent much of its life
with surface liquid water, plate tectonics, and a stable temperate climate. Part of the basis for …

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 …

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 search for life in the Universe is a fundamental problem of astrobiology and modern
science. The current progress in the detection of terrestrial-type exoplanets has opened a …

The increase in solar luminosity over geological timescales should warm the Earth's climate,
increasing water evaporation, which will in turn enhance the atmospheric greenhouse effect …

The presence of valleys on ancient terrains of Mars suggests that liquid water flowed on the
martian surface 3.8 Gyr ago or before. The above-freezing temperatures required to explain …

TRAPPIST-1 planets are invaluable for the study of comparative planetary science outside
our solar system and possibly habitability. Both transit timing variations (TTV) of the planets …