Nereid as a regular satellite of Neptune.
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Where this comes from
- Record sourced from PubMed, PMID 42160409.
- Also identified by DOI 10.1126/sciadv.aeb1429 and PMC identifier 13189092.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Nereid, Neptune's third largest moon, is considered to be a captured irregular satellite because of its highly eccentric orbit. However, among irregular satellites, Nereid is an outlier: It is the largest, the closest to its host planet, and the most eccentric. We present James Webb Space Telescope near-infrared spectroscopy of Nereid that demonstrates that its composition is inconsistent with its suggested captured origin. We then simulate Nereid's early orbital history subsequent to Triton's capture to demonstrate a plausible dynamical pathway for a regular satellite formed in situ around Neptune to evolve to Nereid's present-day orbit. On the basis of the available spectroscopic and dynamical evidence, we propose that Nereid is not a body captured from the Kuiper belt but rather the sole surviving intact regular satellite of Neptune.