Science Test

We get day and night beacuse the earth spins on its axis. This is because there is always o ne half of the earth facing the sun, when it is day. The other half is in the opposite side and has no sunlight availible. Nicalous Copernicuz was the first person to suggest this to people, they did not believe him since he had no evidence. Scientists have developed hi ideas in time and now we can understand why the earth goes around the sun, not the other way round.

Seasons happen because the earth is tilted on its axis. The equator splits the earth in two halves, the northern hemisphere and the southern hemisphere. When the northern hemisphere is tilted towards the sun it is summer because the sun is closer to that part of the earth, and it means that the sun appears higher in the sky. It is winter when it is tilted away. The solstices are the longest and shortests days in a year. The equinoxes are when the lenght of day and night is the same.

The moon is a natural satellite. A satellite is the name given to any object that orbits a larger object, in this case the moon orbits the earth. The moon takes 28 days to complete 1 orbit of the earth, this is known as a lunar month. Our moon is the fifth largest moon in the soar system. It is about a quarter of the earth in diameter. It does not have an atmosphere and it is not a star because it does not give off its on light and heat, it reflects it from the sun which is why it is visible to us.

The moon always has one half facing the sun but this doesn't mean that we can always see it. Since the moon doesn't rotate on its own axis, as the earth, we can only see the part that is facing us at any one time. Since we are moving we see different angles of it at different times.

The 8 Phases of the Moon:

• New Moon
• Waxing Crescent
• First Quater
• Waxing Gibbous
• Full Moon
• Waning Gibbous
• Second Quater
• Waning Crescent
• and back to the start