Context. One of the long-term goals of exoplanet science is the atmospheric characterization
of dozens of small exoplanets in order to understand their diversity and search for habitable …

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 …

Nitrogen dioxide (NO 2) on Earth today has biogenic and anthropogenic sources. During the
Covid-19 pandemic, observations of global NO 2 emissions have shown a significant …

Abstract Nitrous oxide (N 2 O)—a product of microbial nitrogen metabolism—is a compelling
exoplanet biosignature gas with distinctive spectral features in the near-and mid-infrared …

The first potential exoplanetary biosignature detections are likely to be ambiguous due to the
potential for false positives: abiotic planetary processes that produce observables similar to …

Technosignatures refer to observational manifestations of technology that could be detected
through astronomical means. Most previous searches for technosignatures have focused on …

ABSTRACT The Great Oxidation Event was a period during which Earth's atmospheric
oxygen (O2) concentrations increased from∼ 10− 5 times its present atmospheric level …

This paper considers how planetesimal impacts affect planetary atmospheres. Atmosphere
evolution depends on the ratio of gain from volatiles to loss from atmosphere stripping fv; for …

The search for life beyond the Earth is the overarching goal of the NASA Astrobiology
Program, and it underpins the science of missions that explore the environments of Solar …

Recent advances in our understanding of the dynamical history of the Solar system have
altered the inferred bombardment history of the Earth during accretion of the Late Veneer …