Image: Wikimedia Commons

Halimede

Moon of Neptune

Entitymoon of Neptune irregular moonQ19507

Also known as Neptune IX · S/2002 N 1

Instance of: moon of Neptune
, irregular moon

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

Halimede, also known as Neptune IX and previously as S/2002 N 1, is an irregular moon of Neptune. It was discovered on 14 August 2002 by Matthew Holman, JJ Kavelaars, Tommy Grav, Wesley Fraser, and Dan Milisavljevic at Cerro Tololo Inter-American Observatory in Chile. Named after one of the Nereids from Greek mythology, Halimede follows a distant, highly eccentric, and highly inclined orbit with an average orbital period of about 5.1 Earth years. Like the majority of irregular moons, Halimede's orbit is retrograde, meaning it revolves around Neptune in the opposite direction to the planet's orbit around the Sun. It is the second-innermost known retrograde moon of Neptune, after Triton.

Overview

All data

26 statements · 15% with external sources · numbers in brackets are citations

Orbits: Neptune
Provisional designation: S/2002 N 1
Discovered: August 10, 2002
Discovered by: Matthew J. Holman
John J. Kavelaars
Dan Milisavljevic
Named after: Halimede
Semi-major axis: 16.6M km
Color index: 0.73 astronomical filter: B-V colour
1
Sources
1.arxiv.org/abs/astro-ph/0405605
View statement on Wikidata ↗
0.35 astronomical filter: V-R colour
1
Sources
1.arxiv.org/abs/astro-ph/0405605
View statement on Wikidata ↗
Eccentricity: 0.2646
Inclination: 134.1 degree
Orbital period: 1,879.08 days
Diameter: 62 km
Albedo: 0.04
Periapsis: 6,700,000 km
Apoapsis: 24.7M km
Different from: Halimede criterion used: descriptive page and disambiguation page have to be in different items

On other databases

4 identifiers linking Halimede across the web's reference databases

Data quality

statements

15%

externally sourced

Source last edited October 6, 2026. AIDB refreshes this page daily.

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AIDB. (2026). Halimede (Q19507). Retrieved from https://aidb.si/e/halimede-Q19507