### Instruction:
How many planets make up the Solar System?

### Response:
There are 8 planets in the solar system. Mercury is the smallest and closest to the Sun. Venus is the second closest to the Sun. Earth, our home planet, is the third planet closest to the Sun followed by Mars. After the asteroid belt is Jupiter, the fifth and biggest planet in the  Solar System. Saturn, Uranus and Neptune are the last planets in the Solar System.

Originally the Solar System was said to have 9 planets until 2006 when the term "planet" was redefined to exclude "dwarf planets". This results in the exclusion of the ninth and farthest away planet, Pluto, reducing the count of planets in the Solar System to current count of 8.