Introduction

    Neptune is the eighth planet from the Sun.  It is the fourth largest planet in the solar system.  If Earth were the size of the ball used in playing Jacks, Neptune would be the size of a bocci ball.

    Neptune is one of the outer planets.  The others are Jupiter, Saturn, and Uranus.  Neptune can't be seen without a telescope.  Neptune wasn't discovered until 1846.  The planet remained a mystery until a space probe passed by in 1989.

    Neptune is a gas giant like its neighbors, Jupiter, Saturn, and Uranus.  Like them, Neptune is a large planet.  It does not have a solid surface.  It has a deep gaseous