The Earth’s Moon - PowerPoint PPT Presentation

The Earth’s Moon

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

It takes 1 week to go from new to 1st quarter, 1 week to go from 1st 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 is 2 days longer than period of revolution because as the moon orbits Earth, Earth is moving by orbiting the sun

• Moon Phases
• Phases again
• Falling Moon
• How the Moon Formed

Tides

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

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

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

Based on the diagram,

which types of tides have a larger range?

SPRING TIDES

There are not

exactly 12 hours

between high tides

because the moon

revolves around

the Earth while the

Earth rotates