1. Sun/Moon/Earth Study Guide Answers

2. Axis
The imaginary line that the Earth spins on

3. Rotate
to spin on an axis

4. Revolve
to move around the Sun

5. Luminous
to create its own light

6. Illuminated
Not a light source, reflects light

7. Opaque
an object that does not let light pass through

8. Know what causes day and night and how long it takes.
Day and Night are caused by the rotation of the Earth on its axis every 24 hours.
The side of the Earth that is facing the Sun is in day.
Due to the fact that the Earth is an opaque object, the side that is not facing the Sun is in night.

9. The Sun rises in the East and sets in the West.

10. Be able to explain what causes a year and how long it takes.
Years are caused by the revolution of the Earth around the Sun.
It takes about 365 days for the Earth to complete 1 revolution or 1 year.

11. Know the relative positions of the earth, the sun and the moon.

12. Know which objects in the Solar System are luminous and which are illuminated.
SUN
Everything Else
Moon
- planets

13. Know how much of the Earth is in daylight and how much is in darkness at any given time.
1/2

14. Know how long it takes to complete 1 lunar cycle
About 1 month

15. Know why there are different moon phases.
There are different moon phases because…
the Moon revolves around the Earth
the Moon reflects the Sun’s light
it appears to change depending on the position of the Earth, Sun & Moon