Lunar Phases & Tides
Vocabulary
- Waxing
- waning
- crescent
- gibbous
- revolution
Students must know:
· The Moon does not make its own light; it reflects the light from the Sun
· The Sun continuously illuminates half of the Moon’s surface, but varying amounts of it are visible from Earth at any moment
· Changes in visibility of the Moon’s surface follow a predictable pattern called the lunar cycle
· The positions of the Sun, Earth, and Moon as they move through space cause the lunar phases to occur to viewers from Earth
· The Moon revolves around the Earth about every 28 days
· The lunar phases occur in order: new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent
· The lunar phases change about every 3.5 days
Tides
Vocabulary
- Rotation
- high tide
- low tide
- Spring tide
- Neap tide
· There are 2 cycles of high and low tides every 24 hours
· The Moon’s gravity pulls the Earth’s oceans and seas toward it, created a bulge
· A bulge is created on the opposite side because the Moon pulls the Earth toward it
· The tides occur as the Earth rotates on its axis
· Spring tides occur when the Sun and Moon are lined up and the force their gravity together causes high and low tides to be exaggerated
· Neap tides occur when the Sun and Moon are perpendicular to each other (at ninety degrees to the Earth) and the forces are cancelled out, causing not much difference between high and low tide
· Spring tides occur during full and new moons
· Neap tides occur during first and third quearter moons