Direct imaging spectroscopy with future space-based telescopes will constrain terrestrial planet atmospheric composition and potentially detect biosignature gases. One promising indication of life is abundant atmospheric O2.
Nitrogen
![Central panel: ammonia 14N/ 15N map in L1544. The contours show the total gas density at levels N(H2) = [1, 1.5, 2, 2.5] × 1022 cm−2 , obtained from Herschel SED fitting (Spezzano et al. 2017). The black circles show the three offsets (labelled with capital letters) where we compute average spectra to improve S/N. The averaged 15NH3 (1,1) lines are shown in the surrounding panels (black: observations, red: best-fit models, obtained as described in App. B). These panels are labelled in their top-left corner, whilst in the top-right corners we indicate the measured 14N/ 15N. -- astro-ph.GA](https://i0.wp.com/astrobiology.com/wp-content/uploads/2023/06/Nitrogen.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry, Astronomy & Telescopes, Imaging & Spectroscopy, Interstellar, Status Report
Nitrogen Fractionation In Ammonia And Its Insights On Nitrogen Chemistry
Context. Observations of 14N/15N in the interstellar medium are becoming more frequent thanks to the increased telescope capabilities. However, interpreting these data is still puzzling. In particular, measurements of 14N/15N […]
Posted inAstrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Habitable Zones, Origin & Evolution of Life, Status Report
Isotopic Constraints On Lightning As A Source Of Fixed Nitrogen In Earth’s Early Biosphere
Bioavailable nitrogen is thought to be a requirement for the origin and sustenance of life. Before the onset of biological nitrogen fixation, abiotic pathways to fix atmospheric N2 must have […]
Posted inAstrochemistry, Imaging & Spectroscopy, Interstellar, Status Report
Can Pre-supernova Winds From Massive Stars Enrich The Interstellar Medium With Nitrogen At High Redshift?
Understanding the nucleosynthetic origin of nitrogen and the evolution of the N/O ratio in the interstellar medium is crucial for a comprehensive picture of galaxy chemical evolution at high-redshift because […]
Posted inHabitable Zones, Press Release, Space Weather & Heliophysics
The Role of High Energy Photoelectrons on the Dissociation of Molecular Nitrogen in Earth’s Ionosphere
Soft x-ray radiation from the sun is responsible for the production of high energy photoelectrons in the D and E regions of the ionosphere, where they deposit most of their […]
Posted inAstrochemistry, Press Release
Stability of Nitrogen in Planetary Atmospheres in Contact with Liquid Water
Effective deposition velocities in the converged atmosphere-ocean chemistry solutions. Solid lines are from the Sun-like star cases, and dashed lines are from the GJ 876 cases. The effective deposition velocities […]