Samuel Chiltern answered
The planet Neptune is significantly further away from the Sun than Earth and, for this reason, it takes 164.79 Earth years to complete a single orbit.
Neptune is a fascinating planet, which has recently celebrated an exciting anniversary, which I'll explain more about below.
The Discovery of Neptune
Neptune wasn't discovered until 1846, making it the last officially-recognised planet to be discovered in our solar system.
Although, in the past, planets had been discovered by chance, Neptune was the first to be discovered by the work of mathematicians.
Mathematicians John Adams and Urbain Le Verrier were working separately on the problem, and had proposed that certain curiosities in the orbit of Uranus must be due to the presence of another as-yet-undiscovered planet.
Neptune's 'Birthday'
On the 11th of July 2011, astronomers celebrated the passing of the first Neptunian year since the planet was discovered.
The Seasons on Neptune
The seasons on Neptune are extremely pronounced, and this creates incredibly-strong winds on the planet's surface - which have so far been measured at 2100 km/hour.
This intense seasonality is due to Neptune's lengthy years, and to the fact that its axis (the angle at which it rotates) is pointing away from the axis of the Sun. This means that the northern hemisphere is angled towards the sun for half of the year, before the southern hemisphere has its chance to be heated.
This is very similar to how the seasons on Earth work but, on Neptune, this happens over a much longer period of time, which creates much more extreme weather.
Neptune is a fascinating planet, which has recently celebrated an exciting anniversary, which I'll explain more about below.
The Discovery of Neptune
Neptune wasn't discovered until 1846, making it the last officially-recognised planet to be discovered in our solar system.
Although, in the past, planets had been discovered by chance, Neptune was the first to be discovered by the work of mathematicians.
Mathematicians John Adams and Urbain Le Verrier were working separately on the problem, and had proposed that certain curiosities in the orbit of Uranus must be due to the presence of another as-yet-undiscovered planet.
Neptune's 'Birthday'
On the 11th of July 2011, astronomers celebrated the passing of the first Neptunian year since the planet was discovered.
The Seasons on Neptune
The seasons on Neptune are extremely pronounced, and this creates incredibly-strong winds on the planet's surface - which have so far been measured at 2100 km/hour.
This intense seasonality is due to Neptune's lengthy years, and to the fact that its axis (the angle at which it rotates) is pointing away from the axis of the Sun. This means that the northern hemisphere is angled towards the sun for half of the year, before the southern hemisphere has its chance to be heated.
This is very similar to how the seasons on Earth work but, on Neptune, this happens over a much longer period of time, which creates much more extreme weather.