The Earth, Sun and Moon
Gravity
- Glue of the universe
- If two things are placed next to each other they will be attracted to each other
- The larger an object is the more gravitational attraction it has
The Earth, Sun and Moon
- Our planet is constantly moving in an almost circular path around the sun
- It takes a year for the earth to make one revolution => 365.25 days
- The moon is satellite of the earth => 27.3 days
Days
- At any one time only half of the earth is facing the sun
- When facing the sun we have day
- When facing away from the sun we have night
- The earth takes 24 hours to rotate on it’s axis
- The axis is an imaginary line through the earth that goes from south pole to north pole
- The axis is tilted => 23.5 degrees
Phases of the moon
- The moon orbits the earth every 27.3 days
- The moon also rotates on it’s axis every 27.3 days
- This m
- eans the same side of the moon is also facing the earth
There are 8 phases of the moon
- Day 1: New moon
- Day 2-6: Waxing crescent
- Day 7: First quarter
- Day 8-13: Waxing gibbous
- Day 14: Full moon
- Day 15-20: Waning gibbous
- Day 21: Third quarter
- Day 22-26: Waning crescent
- Day 27: New moon and cycle repeated
Eclipses
Solar eclipse
- Moon comes between earth and sun
- Can only happen if the earth passes through the shadow of the moon
Lunar eclipse
- Earth comes between sun and moon
- Only during a full moon
- Moon has to go through the earth’s shadow