The Earth’s Moon

Motions of Earth’s Moon Revolution of the moon around Earth affects: phases of the moon, tides and eclipses Revolution of the moon around Earth affects: phases of the moon, tides and eclipses The moon’s orbit is tilted at 5 degrees The moon’s orbit is tilted at 5 degrees The moon’s period of revolution is 27.5 days The moon’s period of revolution is 27.5 days The moon rotates at the same speed that it revolves, so the same side of the moon is always facing Earth The moon rotates at the same speed that it revolves, so the same side of the moon is always facing Earth

Phases The moon rises 50 minutes later each day The moon rises 50 minutes later each day Half of the moon is always lit (except during a lunar eclipse) due to the light from the sun Half of the moon is always lit (except during a lunar eclipse) due to the light from the sun Depending on where the moon is in it’s orbit, observers on Earth see varying amounts of the lighted half Depending on where the moon is in it’s orbit, observers on Earth see varying amounts of the lighted half

WHEN IN DOUBT, CHECK IT OUT! ESRT page 15

Phases of the Moon Moon PhaseTime in days for one phase cycle Tides (spring or neap) Eclipse Possible? 1. New0SpringYes, Lunar 2. New crescent3.75No 3. First quarter (half) 7.5NeapNo 4. New gibbous11.25No 5. Full14.5SpringYes, Solar 6. Old gibbous18.5No 7. Third quarter (half) 22.5NeapNo 8. Old cresent26No 1. New29.5SpringYes, Lunar

It takes 1 week to go from new to 1 st quarter, 1 week to go from 1 st quarter to full (or 2 weeks total), etc It takes 1 week to go from new to 1 st quarter, 1 week to go from 1 st quarter to full (or 2 weeks total), etc It takes 29.5 days for the moon to go from the new moon phase, through all of the other phases, back to the new moon phase- It takes 29.5 days for the moon to go from the new moon phase, through all of the other phases, back to the new moon phase- It is 2 days longer than period of revolution because as the moon orbits Earth, Earth is moving by orbiting the sun It is 2 days longer than period of revolution because as the moon orbits Earth, Earth is moving by orbiting the sun

Vids Moon Phases Moon Phases Moon Phases Moon Phases Phases again Phases again Phases again Phases again Falling Moon Falling Moon Falling Moon Falling Moon How the Moon Formed How the Moon Formed How the Moon Formed How the Moon Formed

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

Spring Tides / Neap Tides Spring Tides: When the highest high tides and the lowest low tides occur, which happens near the full and new moon phases Spring Tides: When the highest high tides and the lowest low tides occur, which happens near the full and new moon phases This is due to the sun and the moon pulling in the same line This is due to the sun and the moon pulling in the same line Neap Tides: Least amount of change between high tide and low tide- occurs during the first and last quarter phases of the moon Neap Tides: Least amount of change between high tide and low tide- occurs during the first and last quarter phases of the moon

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