What Planet Takes The Longest Time To Revolve Around The Sun?

The planet that takes the longest to orbit the sun is Neptune.

How Long Does Neptune Take To Orbit The Sun?
Neptune takes 165 Earth years to complete its orbit. It is the furthest planet from the sun, and so it makes sense that its orbit would take the longest!

Facts About Neptune

• Neptune was discovered on 23rd September 1846.
• In terms of diameter, Neptune is the fourth-largest planet in the solar system.
• The temperature of Neptune's atmosphere falls as low as −221.4 °C
• Neptune can become as hot as 5,000K on the inside!
• Neptune has 3 main rings.

What About Pluto?
Pluto used to be the planet with the longest orbit but, as of 2006, it no longer meets the criteria required to be classified as a planet, as it is too small.

Pluto takes 248 Earth years to complete its orbit, as it's even further away from the sun than Neptune is!