CHAPTER 1 The Solar System and BEYOND In 2014 astronomers made an amazing discovery They found Kepler 186f a new planet The planet is Earth sized It's also in its star's habitable zone Being in this zone means it could have liquid water The planet might be rocky too And if a rocky planet has water it might have life
The Three Rules for Planets Bodies in space must follow three rules to be called planets RULE ONE It must orbit a star RULE TWO It must be mostly round RULE THREE Its path must be clear of smaller objects
Planets Planets are large bodies that orbit stars Stars gravity holds planets in their paths Earth and seven other planets circle the sun They make up Earth's solar system
