Sadly, because the scientists in the world no longer count Pluto as a planet, Neptune is the last planet in our solar system. It is an ice giant and is the 8th planet from the sun. The cool thing about this planet is that it was “located through mathematical predictions rather than through regular observations of the sky” (NASA). This means that math predicted there should be a planet in X place in space and boom, there was Neptune. That is truly impressive.
Neptune is so far away from the sun that it takes almost 165 years to orbit it. In fact, since its discovery in 1846, it has only made one orbit (that ended in 2011). It only takes 16 Earth hours to make one rotation, though.
Neptune is made of water, ammonia, and methane. Like Uranus, it gets its blue color from methane. Because Neptune has a much brighter blue it means there is some other component at work as well. This component is still unknown, however.
It has thirteen confirmed moons and six rings. Triton is Neptune’s largest moon and it travels in the opposite direction of the other moons.
I got this information from NASA’s Solar System Exploration site.