Evidence for Surprising Heavy Nitrogen Isotopic Enrichment in Comet 46P/Wirtanen’s Hydrogen Cyanide
Year: 2024
Type: article
Abstract: 46P/Wirtanen is a Jupiter-family comet, probably originating from the solar system’s Kuiper Belt, that now resides on a 5.4 yr elliptical orbit. During its 2018 apparition, comet 46P passed unusually close to the Earth (within 0.08 au), presenting an outstanding opportunity for close-up observations of its inner coma. Here we present observations of HCN, H13CN, and HC15N emission from 46P using the Atacama Compact Array. The data were analyzed using the SUBLIME non-LTE radiative transfer code to derive 12C/13C and 14N/15N ratios. The HCN/H13CN ratio is found to be consistent with a lack of significant 13C fractionation, whereas the HCN/HC15N ratio of 68 ± 27 (using our most conservative 1σ uncertainties), indicates a strong enhancement in 15N compared with the solar and terrestrial values. The observed 14N/15N ratio is also significantly lower than the values of ∼140 found in previous comets, implying a strong 15N enrichment in 46P’s HCN. This indicates that the nitrogen in Jupiter-family comets could reach larger isotopic enrichments than previously thought, with implications for the diversity of 14N/15N ratios imprinted into icy bodies at the birth of the solar system.
Source: The Planetary Science Journal
DOI: 10.3847/psj/ad7829
Language: English
Topic: Astro and Planetary Science
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,800
Funders: National Science Foundation, National Aeronautics and Space Administration, National Radio Astronomy Observatory, National Science Council, Korea Astronomy and Space Science Institute, National Astronomical Observatory of Japan, National Science and Technology Council, National Institutes of Natural Sciences, Planetary Science Division
Awards: IGF::OT::IGF CRESST IITHE GODDARD CENTER FOR RESEARCH AND EXPLORATION IN SPACE SCIENCE AND TECHNOLOGY (CRESST) II WILL CARRY OUT OBSERVATIONAL EXPERIMENTAL AND THEORETICAL RESEARCH IN SUPPORT OF NASA STRATEGIC SCIENCE MISSION OBJECTIVES RELATING TO:A.THE SOLAR SYSTEM STARS GALAXIES AND THE UNIVERSE AT LARGE;B.THE INFORMATIONAL AND COMPUTATIONAL SCIENCES RELATED TO THE UNIQUE NEEDS OF DATA SYSTEMS REQUIRED TO INTERPRET DATA FROM THE SPACE SCIENCES; ANDC.THE DEVELOPMENT OF THE TECHNOLOGY REQUIRED TO ACHIEVE THESE SCIENTIFIC CHALLENGES.THIS COOPERATIVE AGREEMENT WILL ALLOW FOR SUBSTANTIAL PROGRAMMATIC INVOLVEMENT IN THE FORM OF COLLABORATION BETWEEN GSFC AND THE CRESST II AS WELL AS JOINT DEVELOPMENT OF RESEARCH OBJECTIVES.THE GOAL IS TO ESTABLISH A FOCUSED PARTNERSHIP THAT:A.BRINGS TOGETHER GSFC AND EXTERNAL SCIENTISTS TO IMPLEMENT THE NASA STRATEGIC GOAL IN SPACE SCIENCE;B.BUILDS ON THE CAPABILITIES AND STRENGTHS OF PARTICIPATING ORGANIZATION IN SPACE SCIENCE;C.PROVIDES ORGANIZATION AND STAFFING FLEXIBILITY TO ADAPT TO EVOLVING RESEARCH PROGRAM NEEDS;D.INCREASES THE INVOLVEMENT OF MINORITY AND WOMEN SCIENTISTS IN SPACE SCIENCE RESEARCH; ANDE.FACILITATES ACCESS TO STUDENT TALENT AND PROVIDES OPPORTUNITIES FOR THEIR PARTICIPATION IN NASA PROGRAMS.A BROAD AND VIGOROUS SPACE RESEARCH PROGRAM IN NASA IS VITAL FOR THE ADVANCEMENT OF KNOWLEDGE. SCIENTISTS AT NASA IN COLLABORATION WITH OUTSIDE SCIENTISTS PLAY A KEY ROLE IN CONCEIVING NEW SPACE MISSIONS PROVIDING MISSION REQUIREMENTS AND ACHIEVING RESEARCH OBJECTIVES AIMED AT UNDERSTANDING THE ORIGINS STRUCTURE AND EVOLUTION OF SYSTEMS IN THE UNIVERSE AND EXPLORING THE SOLAR SYSTEM.THE CRESST II WILL FOCUS PRIMARILY ON SCIENTIFIC RESEARCH. IT IS EXPECTED TO STRENGTHEN COOPERATIVE RELATIONSHIPS BETWEEN THE RECIPIENT AND GOVERNMENT SCIENTISTS IN THE GODDARD SCIENCES AND EXPLORATION DIRECTORATE (SED) AND WILL PROVIDE A VEHICLE TO INCREASE THE INVOLVEMENT OF THE EXTERNAL SCIENCE COMMUNITY IN THE PURSUIT OF NASA GOALS.THE CRESST II WILL CONDUCT RESEARCH COLLABORATIVELY WITH ORGANIZATIONAL ELEMENTS WITHIN THE GODDARD SED (CODE 600). RESEARCH MAY INVOLVE ANALYSIS OF DATA FROM OPERATING AND PAST MISSIONS AND MODELING AND DESIGN OF MISSIONS PLANNED OR UNDER DEVELOPMENT. FUTURE RESEARCH ACTIVITIES WILL EVOLVE AS A FUNCTION OF PRIORITIES BUDGETS FUNDING OPPORTUNITIES AND SUCCESS OF PROPOSAL SUBMISSIONS., A SUBLIME 3D Model for Non-LTE Emission from Cometary and Icy Moon Atmospheres, Collaborative Research: Pushing the Boundaries of Post-Rosetta Cometary Science with the New Generation of Near-Infrared Spectrographs
OpenAlex ID: W4403203594