- Neptune is the 4th biggest planet in the Solar System by diameter, but the 3rd largest by mass.
- Neptune is the 8th planet and the last of the recognized planets from the Sun
- It's a gas giant, it has a radius of 24,622 km, or nearly 4 times that of Earth
- Neptune was not dicovered until September 23 1846.. It was first found by mathematical prediction due to unexpected changes in the orbit of the planet Uranus!
- Neptune has 13 known moons
- Voyager 2 is the only space craft to have visited Neptune, it did so in August 1989. Signals from Voyager 2 took over 4 hours ( or 246 minutes) to reach the Earth!
- A day on Neptune is roughly 16.11 hours
- Neptune takes an average of 164.79 years years to go around the Sun. This means that a season lasts for 40 earth years.