The Earth’s MoonThe Earth’s Moon

Motions of Earth’s MoonMotions of Earth’s Moon

Revolution of the moon around Earth Revolution of the moon around Earth affects: phases of the moon, tides and affects: phases of the moon, tides and eclipseseclipses

The moon’s orbit is tilted at 5 degreesThe moon’s orbit is tilted at 5 degreesThe moon’s period of revolution is 27.5 The moon’s period of revolution is 27.5

daysdaysThe moon rotates at the same speed that The moon rotates at the same speed that

it revolves, so the same side of the moon it revolves, so the same side of the moon is always facing Earthis always facing Earth

PhasesPhases

The moon rises 50 minutes later each dayThe moon rises 50 minutes later each dayHalf of the moon is always lit (except Half of the moon is always lit (except

during a lunar eclipse) due to the light from during a lunar eclipse) due to the light from the sun the sun

Depending on where the moon is in it’s Depending on where the moon is in it’s orbit, observers on Earth see varying orbit, observers on Earth see varying amounts of the lighted halfamounts of the lighted half

WHEN IN DOUBT, CHECK IT WHEN IN DOUBT, CHECK IT OUT! ESRT page 15OUT! ESRT page 15

Phases of the MoonPhases of the Moon

Moon Phase Time in days for one phase cycle

Tides (spring or neap)

Eclipse Possible?

1. New 0 Spring Yes, Lunar

2. New crescent 3.75 No

3. First quarter (half)

7.5 Neap No

4. New gibbous 11.25 No

5. Full 14.5 Spring Yes, Solar

6. Old gibbous 18.5 No

7. Third quarter (half)

22.5 Neap No

8. Old cresent 26 No

1. New 29.5 Spring Yes, Lunar

It takes 1 week to go from new to 1It takes 1 week to go from new to 1stst quarter, quarter, 1 week to go from 11 week to go from 1stst quarter to full (or 2 quarter to full (or 2 weeks total), etcweeks total), etc

It takes 29.5 days for the moon to go from It takes 29.5 days for the moon to go from the new moon phase, through all of the the new moon phase, through all of the other phases, back to the new moon phase-other phases, back to the new moon phase-

It is 2 days longer than period of revolution It is 2 days longer than period of revolution because as the moon orbits Earth, Earth is because as the moon orbits Earth, Earth is moving by orbiting the sunmoving by orbiting the sun

VidsVids

Moon PhasesMoon PhasesPhases againPhases againFalling MoonFalling MoonHow the Moon FormedHow the Moon Formed

Tides: The cyclic rise and fall of Tides: The cyclic rise and fall of ocean waters due to the gravitation ocean waters due to the gravitation between the Earth, the moon and between the Earth, the moon and the sunthe sun

Spring Tides / Neap TidesSpring Tides / Neap Tides Spring Tides: When the highest high tides Spring Tides: When the highest high tides

and the lowest low tides occur, which and the lowest low tides occur, which happens near the full and new moon phaseshappens near the full and new moon phases

This is due to the sun and the moon pulling in This is due to the sun and the moon pulling in the same linethe same line

Neap Tides: Least amount of change Neap Tides: Least amount of change between high tide and low tide- occurs during between high tide and low tide- occurs during the first and last quarter phases of the moonthe first and last quarter phases of the moon

The sun is larger, but The sun is larger, but the moon is closer, so the moon is closer, so the moon has a much the moon has a much greater effect on the greater effect on the tidestides