- Neptune is the eighth and farthest known Solar planet from the Sun.
- In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, and the densest giant planet.
- It is 17 times the mass of Earth, slightly more massive than its near-twin Uranus.
- Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere.
- The planet orbits the Sun once every 164.8 years at an average distance of 30.1 AU (4.5 billion km; 2.8 billion mi).
- The Planet is named after the Roman god of the sea.
- Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation.
- Neptune’s weather is characterized by extremely dynamic storm systems, with winds reaching speeds of almost 600 m/s (2,200 km/h; 1,300 mph)—nearly reaching supersonic flow.
- Neptune has 14 known moons. Triton is the largest Neptunian moon, comprising more than 99.5% of the mass in orbit around Neptune.
- The average distance between Neptune and the Sun is 4.5 billion km (about 30.1 astronomical units (AU)), and it completes an orbit on average every 164.79 years, subject to a variability of around ±0.1 years.
Also Read Facts about other planets in Solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune