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Stellar SEDs from 0.3 to 2.5 μm: Tracing the Stellar Locus and Searching for Color Outliers in the SDSS and 2MASS
The Sloan Digital Sky Survey (SDSS) and Two Micron All Sky Survey (2MASS) are rich resources for studying stellar astrophysics and the structure and formation history of the Galaxy. As new surveys
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic
The Evolution of Solar Flux from 0.1 nm to 160 μm: Quantitative Estimates for Planetary Studies
Understanding changes in the solar flux over geologic time is vital for understanding the evolution of planetary atmospheres because it affects atmospheric escape and chemistry, as well as climate.
Nitrogen-enhanced greenhouse warming on early Earth
Early in Earth’s history, the Sun provided less energy to the Earth than it does today. However, the Earth was not permanently glaciated, an apparent contradiction known as the faint young Sun
A bistable organic-rich atmosphere on the Neoarchaean Earth
It has been hypothesized that, before widespread oxygenation about 2.45 billion years ago, the Earth’s atmosphere contained an organic haze similar to that on Titan. However, these theoretical
Biogeochemical modelling of the rise in atmospheric oxygen
Understanding the evolution of atmospheric molecular oxygen levels is a fundamental unsolved problem in Earth's history. We develop a quantitative biogeochemical model that simulates the
Atmospheric origins of perchlorate on Mars and in the Atacama
[1] Isotopic studies indicate that natural perchlorate is produced on Earth in arid environments by the oxidation of chlorine species through pathways involving ozone or its photochemical products.
The Pale Orange Dot: The Spectrum and Habitability of Hazy Archean Earth
TLDR
Coupled climate-photochemical-microphysical simulations demonstrate that hazes can cool the planet's surface by about 20 K, but habitable conditions with liquid surface water could be maintained with a relatively thick haze layer even with the fainter young Sun, and find that optically thicker hazes are self-limiting due to their self-shielding properties, preventing catastrophic cooling of the planet.
Onset of the aerobic nitrogen cycle during the Great Oxidation Event
TLDR
The interpretation of the nitrogen isotope data in the context of iron speciation and carbon isotopeData suggests biogeochemical cycling across a dynamic redox boundary, with primary productivity fuelled by chemoautotrophic production and a nitrogen cycle dominated by nitrogen loss processes using newly available marine oxidants.
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