Nitrogen Archives

c. Approximate ages for the origin of nitrogenase isoforms are based on geochemical12 and phylogenetic data. -- biorxiv.org

Astrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Resurrected Nitrogenases Recapitulate Canonical N-isotope Biosignatures Over Two Billion Years

by Keith CowingNovember 12, 2025June 10, 2026

Nitrogen isotope fractionation (ε15N) in sedimentary rocks has provided evidence for biological nitrogen fixation, and thus primary productivity, on the early Earth.

Position velocity map of Hydrogen recombination line emission for the observed GOT C+ LOS between l = −100◦ and 100◦ at b = 0◦ . The position– velocity map is overlaid with projections of the Scutum–Crux, Sagittarius–Carina, Perseus, and Norma–Cygnus Milky Way spiral arms. -- astro-ph.GA

Astrochemistry, Imaging & Spectroscopy, Interstellar, Status Report

Nitrogen Abundance Distribution in the Inner Milky Way

by Keith CowingJuly 23, 2024July 22, 2024

We combine a new Galactic plane survey of Hydrogen Radio Recombination Lines (RRLs) with far-infrared (FIR) surveys of ionized Nitrogen, N+, to determine Nitrogen abundance across Galactic radius.

A microscope image of a dark Bennu particle, about a millimeter long, with a crust of bright phosphate. To the right is a smaller fragment that broke off. Credits: From Lauretta & Connolly et al. (2024) Meteoritics & Planetary Science, doi:10.1111/maps.14227.

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Meteorites & Asteroids, Missions & Hardware, Press Release, Sample Return

An OSIRIS-REx Asteroid Sample Has Surprising Phosphate Content

by Keith CowingJune 27, 2024June 27, 2024

Scientists have eagerly awaited the opportunity to dig into the 4.3-ounce (121.6-gram) pristine asteroid Bennu sample collected by NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer) […]

Predicted log(N/O) vs log(O/H)+12 for GN-z11. Different evolutionary tracks represent different Pop III star-forming clumps, which merge into the main-branch of the galaxy. The tracks are colour-coded in time (left) and stellar mass (right). The light-purple trapezoid, the dark-purple rectangle and the grey stripe represent the conservative and fiducial results for the abundances of GN-z11 by Cameron et al. (2023). The blue points are the photoionisation modelling results for GN-z11 by Senchyna et al. (2023). -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Interstellar, Status Report

The Earliest Phases of CNO Enrichment in Galaxies

by Keith CowingJune 24, 2024June 24, 2024

Context. The recent detection of nitrogen-enhanced, metal-poor galaxies at high redshift by the James Webb Space Telescope has sparked renewed interest in exploring the chemical evolution of carbon, nitrogen, and […]

Reprocessed images of Uranus [L]] and Neptune [R] NASA/JPL-Caltech (Uranus and Neptune); “Modelling the Seasonal Cycle of Uranus’s Colour and Magnitude, and Comparison with Neptune,” by Patrick G. J. Irwin et al., in Monthly Notices of the Royal Astronomical Society, Vol. 527, No. 4; February 2024 (reprocessed images)

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Gas Giants, Ice Giant, Icy Worlds, Neptune, Status Report, Uranus

Insights on the Formation Conditions of Uranus and Neptune from their Deep Elemental Compositions

by Keith CowingJune 20, 2024May 12, 2025

This study, placed in the context of the preparation for the Uranus Orbiter Probe mission, aims to predict the bulk volatile compositions of Uranus and Neptune. Using a protoplanetary disk […]

Nitrogen NLTE (filled circles) and LTE (open circles) abundances log εN of the sample stars. The dotted line corresponds to the solar abundance recommended by Lodders (2021). -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Imaging & Spectroscopy, Status Report

Non-LTE Abundances Of Nitrogen In The Sun And Reference A-F Type Stars

by Keith CowingJune 20, 2024June 20, 2024

A new model atom of nitrogen was developed using the energy levels of N I from laboratory measurements and also predicted in atomic structure calculations and the most up-to-date atomic […]

Abundance ratios as a function of [O/H] colour coded according to the stellar metallicity. The panels show the [X1/X2] ratios calculated correcting the abundances from the trends with the stellar effective temperature (see discussion in the text). The black dashed lines indicate the solar values. -- astro-ph.EP

Ariel Mission, Astrochemistry, Exoplanets, -moons, -comets, Interstellar, Missions & Hardware, Status Report, Stellar Cartography

Ariel Stellar Characterisation II. Chemical Abundances of Carbon, Nitrogen, and Oxygen for 181 Planet-host FGK Dwarf Stars

by Keith CowingJune 19, 2024October 16, 2024

One of the ultimate goals of the ESA Ariel space mission is to shed light on the formation pathways and evolution of planetary systems in the Solar neighbourhood. Such an […]

a–c The N abundance and (d–f) δ15N in the bulk silicate reservoir as a function of the residual N fraction after evaporation. (a, d) Under relatively reducing conditions; (b, e) Relatively oxidizing conditions. (c, f) The modeled N concentration and δ15N in the bulk silicate part at the oxygen fugacity (log fO2) of Earth’s accreting materials (~IW-3 to IW-1). Earth’s core/mantle mass ratio was also used for models in (a) and (b). The fO2 affects the N partition coefficient between metal and silicate (Dmetal/silicateN) and the N species in silicate melts21,22,24,31,33, which consequently controls the equilibrium N isotope fractionation between vapor (N2) and silicate melt (103lnαN2-silicate) (Fig. 1c). The green areas represent the values of the bulk silicate Earth. The red and blue lines in upper panels represent the initial N concentrations (Cinit) of 500 and 1000 ppm in planetesimals before evaporation, respectively. The dash lines refer to the modeling results at different Dmetal/silicateN values. The yellow, blue, and red shadow regions in the lower panels represent the modeled δ15N in the bulk silicate reservoir with an initial δ15N (δ15Ninit) of +20‰, 0‰, and −20‰, respectively. -- Nature Communications

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Status Report

Shaping Earth’s Initial Nitrogen Budget

by Keith CowingJune 18, 2024June 18, 2024

The relative roles of protoplanetary differentiation versus late accretion in establishing Earth’s life-essential volatile element inventory are being hotly debated.

The stellar yields of nitrogen (left) and oxygen (right) for Pop III and very low-metallicity (Z = 10−5 ) stars, for different initial rotations and from different authors (Ekström et al. 2012; Limongi & Chieffi 2012; Murphy et al. 2021a, Sibony et al. submitted). The ranges of initial equatorial velocities corresponding to the different coloured curves are indicated. -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Status Report

Rapidly-rotating Population III Stellar Models As A Source Of Primary Nitrogen

by Keith CowingApril 26, 2024April 26, 2024

The first stars might have been fast rotators. This would have important consequences for their radiative, mechanical and chemical feedback.

a, Backscattered electron image of a fine Ryugu grain. The white boxes correspond to the areas shown in b and c. b, Secondary electron image of framboidal magnetite showing granular texture. c, Secondary electron image of porous iron sulfide surrounded by phyllosilicate. The arrow points to an iron whisker on the iron sulfide surface. Sample ID is A0104-021012.

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Meteorites & Asteroids, Origin & Evolution of Life, Press Release

Meteorites Were A Likely Source Of Nitrogen For Early Earth

by Keith CowingDecember 2, 2023December 2, 2023

Micrometeorites originating from icy celestial bodies in the outer Solar System may be responsible for transporting nitrogen to the near-Earth region in the early days of our solar system. That […]