Halimede

Halimede — moon orbiting Neptune, explore its interactive 3D model in Cosmoscope.

Explore Halimede in a live 3D Solar System. Follow its calculated motion and inspect real astronomical data, distances and orbital facts.

A small grey moon looping backwards around Neptune every 5.1 years, about 17 million km out on average. Its colour matches Nereid’s, so it may be a fragment knocked off Nereid long ago. Its path here is the real tilted, stretched ellipse as it is today.

Radius

~21 km

Orbit

16.6 million km from Neptune

Period

5.1 years — retrograde

Discovered

2002 — Holman, Kavelaars, Grav and colleagues, Chile

Orbit shape

Backwards, tilted and stretched; the Sun’s pull keeps changing it

Colour

Grey like Nereid — perhaps a chip knocked off it

Size

About 42 km across, estimated from its brightness

Explore Halimede in 3D

Cosmoscope places Halimede in the Solar System using astronomical ephemeris or orbital elements, updated for the simulation time. Explore its calculated motion, distance and orbital facts in the interactive 3D view. Accuracy depends on the orbital model and its valid time range.