Used with permission of V.Morris, 
                        Phillips Preparatory School
             A. What is Astronomy?
    1. Astronomy is the study of the universe.
        –This includes planets, stars, galaxies, black 
          holes, moons, meteors, comets, asteroids and 
          all of the matter that exists in space. 
    2. Astronomers are scientists who observe & 
        study space.
                        Used with permission of V.Morris, 
                          Phillips Preparatory School
               B. Modern Calendar
    1.   Our modern calendar is based on the 
         observations of bodies in our solar system.
    2. A year is the time it takes for the Earth to orbit 
         the sun; year = revolution.
    3. A month is the time it takes for the moon to orbit 
         the Earth.
    4. A day is the time it takes for the Earth to rotate 
         once on its axis; day = rotation.
                         Used with permission of V.Morris, 
                          Phillips Preparatory School
    The Size and Scale of our Universe
    It is important to consider scale when we 
        think about the universe.
    Stars appear to be very small when viewed 
        from Earth, but they are actually very 
        large, some, like our sun, are bigger than 
        Earth.
                      Used with permission of V.Morris, 
                        Phillips Preparatory School
      The Scale of our Solar System
              Earth
                      Used with permission of V.Morris, 
                        Phillips Preparatory School