Moon Phases and Tides

The moon glows at night because it reflects sunlight. The sun always lights half of the moon but because the positions of the earth and moon change, we see a different part of the lighted side of the moon every night. The changes in appearance of the moon are called moon phases. When the moon is getting larger in appearance each night, it is waxing (which means ‘growing’). When the moon is getting smaller, it is waning (which means ‘shrinking’).

The moon is waxing from new moon until the full moon and is waning from the full moon until the new moon. A lunar cycle, which is 29.5 days, is how long it takes the moon to complete all eight phases.

Tides:

While the Earth’s gravity pulls on the moon, keeping it in orbit, the moon’s gravity also pulls on Earth. This causes tides, which are the regular rise and fall of ocean water levels. When the sun and moon are on opposite sides of the Earth (full moon and new moon), you will have the highest high tides and lowest low tides. When the sun and moon are at right angles to each other as compared to Earth (first quarter and last quarter) you will have the weakest tides.