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Moon of Neptune — an irregular, distant moon

Halimede

Open in Ouranos

A moon of Neptune.

At Neptune.

Measured

Goes round once every
1,880 days
Distance from Neptune
about 16,590,500 km (its orbit's average)
Orbit
backwards (retrograde), inclined 120°, eccentricity 0.521
JPL / NAIF id
809

How far, from the Earth

About 29.3 AU. To cross it:

  • Light4 hours 3 minutes
  • Voyager 1's speed8.22 years
  • Driving at 100 km/h4,990 years

Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.

Facts

  • Its size is not well measured.

Where this comes from

  • Moons: JPL Planetary Satellite Mean Elements and Physical Parameters, paced to JPL Horizons. NASA/JPL-Caltech. Sizes JPL leaves out are estimates, mostly from brightness: Scott Sheppard's moon pages at Carnegie.

Every catalogue Ouranos draws is credited on the credits page.