Links
- Wikipedia
- Nereid on Wikipedia
Nereid
Details
Nereid is a distant irregular moon of Neptune with one of the most eccentric moon orbits in the Solar System. Its 360-day path suggests either capture from elsewhere or a major disturbance during the capture of Triton.
Nereid matters because its story is written mostly in its orbit. It was discovered from Earth in 1949, long before Voyager 2 revealed Neptune's smaller inner moons, and it remained one of the system's few known satellites for decades.
What makes Nereid unusual is how far and unevenly it travels around Neptune. NASA describes it as one of Neptune's outermost known moons and notes that it takes about 360 Earth days to complete one orbit. That path is among the most eccentric of any moon in the Solar System, so the satellite does not read like a calm regular moon formed neatly in place.
That is why Nereid belongs on this scale. Its size makes it a real small world, but its value comes from dynamical history: it may be a captured asteroid or Kuiper Belt object, or it may have been disturbed onto its strange path when Triton was captured. Nereid turns Neptune's moon system into evidence of disturbance rather than a tidy family portrait.
149km
Visual creditscaleofspace.org / CC BY-NC 4.0
Key facts
- Category
- Moons
- Object class
- Irregular outer moon
- Scale fact
- 340 kmmean diameter
- Host
- Neptune
Scale context
Where Nereid sits on the full axis
Together, these objects make the size change around Nereid easy to compare at a glance.
Sources
References for Nereid
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, please let us know.
- Nereid — Wikipedia
- Visual: scaleofspace.org / CC BY-NC 4.0
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About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.