1. Earth ,Moon,and Sun
By: Jessica Pilot

2.   DAY AND NIGHT
  When the world spins on its axis it causes night and day.  When the earth rotates towards the east the sun seems to move towards the west across the sky. It takes about 24 hours for the world to rotate once on its axis.

3. YEARS
  In addition to the earth rotating on its axis it also travels around the sun. This is called revolution. It is the movement of one object around another. One complete rotation around the sun is a year. Earth travels on its orbit or its path that leads it around the sun. Earth’s orbit is not quite a circle; it’s more of an oval shape. The ancient Egyptians astronomers counted the number of days between each first appearance of the star Sirius. In this way, they found that there are about 365 days in a year and on the forth year there was an extra day so that called this year the “Leap Year”.

4. SEASONS
   Most places outside of the tropics have 4 distinct seasons: winter, spring, summer, and autumn. Not all places have all four seasons because it is warmer near the equator than it is near the north and south poles.