# Neptune

By [Enoq](https://paragraph.com/@enoq) · 2024-01-17

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**Neptune** is the eighth and farthest [planet](https://en.wikipedia.org/wiki/Planet) from the [Sun](https://en.wikipedia.org/wiki/Sun). It is the [fourth-largest planet](https://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size) in the [Solar System](https://en.wikipedia.org/wiki/Solar_System) by diameter, the third-most-massive planet, and the densest [giant planet](https://en.wikipedia.org/wiki/Giant_planet). It is 17 times the [mass of Earth](https://en.wikipedia.org/wiki/Mass_of_Earth), and slightly more massive than its near-twin [Uranus](https://en.wikipedia.org/wiki/Uranus). Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere. Being composed primarily of gases and liquids, it has no well-defined solid surface. The planet orbits the Sun once every 164.8 [years](https://en.wikipedia.org/wiki/Julian_year_\(astronomy\)) at an [orbital distance](https://en.wikipedia.org/wiki/Orbital_distance) of 30.1 [astronomical units](https://en.wikipedia.org/wiki/Astronomical_unit) (4.5 billion kilometres; 2.8 billion miles). It is named after [the Roman god of the sea](https://en.wikipedia.org/wiki/Neptune_\(mythology\)) and has the [astronomical symbol](https://en.wikipedia.org/wiki/Astronomical_symbol) , representing [Neptune's trident](https://en.wikipedia.org/wiki/Trident_of_Poseidon).

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*Originally published on [Enoq](https://paragraph.com/@enoq/neptune)*