Phases, Eclipses, & Tides The moon is Earth’s closest neighbor out in space at

384,400 kilometers out in space or 30 Earths lined up in a row.

The moon revolves around the Earth as the Earth revolves around the sun.

★ The positions of the moon, Earth, & the sun cause the phases of the moon, eclipses, and tides.

Motions of the Moon:As the moon revolves around the Earth it

rotates on its own axis; its orbit similar to Earth’s as a flat oval, tilted at about 7˚.

The moon takes about 27.3 days to orbit around the Earth; it also takes 27.3 days to complete one revolution on its own axis causing a moon “day” & a moon “year” to be the same length of time.

The moon & Earth have synchronous rotation, meaning the same side of the moon always faces Earth.

The “far side” of the moon always faces away from Earth & is never seen.

Phases of the Moon: The moon does not produce its own light, instead it reflects the light from

the sun. The moon has 8 phases and goes through the whole set once a month, or

29.5 days. What Causes Phases?

★The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth.

The Cycles of the Phases:From one full moon to the next it takes about 29.5

days.The 8 phases of the moon in order are: New

Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, Waning Crescent.

Eclipses★When the moon’s shadow hits Earth or Earth’s

shadow hits the moon, an eclipse occurs.There are 2 types of eclipses: solar (sun) eclipse &

lunar (moon) eclipse.The type of eclipse is named for what is being blocked

from Earth.

Total solar eclipse Total lunar eclipse

Solar EclipseThe umbra is the darkest and smallest part of the shadow &

is cone shaped (total darkness).The penumbra is the largest part of the shadow

(partial darkness).Total Solar Eclipse:

○ Only people in the umbra experience a total solar eclipse.

Partial Solar Eclipse:○ In the penumbra, people only see a partial eclipse; since

part of the sun is still visible, it is not safe to look directly at the eclipse.

Lunar Eclipse During a full moon the

Earth blocks the sun’s light from reaching the moon making the moon look dark from Earth.

Total Lunar Eclipse○ When the moon is in the Earth’s umbra, there is

a total lunar eclipsePartial Lunar Eclipse

○ The moon passes partly into the umbra of the Earth’s shadow.

Do-Now Come in quietly Take out notebook. Continue notes from Friday Answer the following question Explain the difference between spring tide and

neap tides? When copying notes BLUE IS FOR YOU. Goes in

your notebook. Drawing so have plenty of room in notes. Virtual

Lesson and Exit Slip after.

SPRING TIDESSpring tides occur at full moon & one at

new moon.The combined force of the sun & moon’s

gravity make a tide with the most intense difference between high & low tides.

Spring Tide is the HIGHEST HIGH and the lowest low

DRAW IT FULL MOON SPRING TIDE At a full moon the moon and sun are on

opposite sides of the Earth. Since they are pulling in a straight line high tides occur. Think of a tug of where the Earth is the prize and both teams are pulling with equal force.

DRAW IT Spring Tide New Moon SPRING TIDE- During the New Moon

The Sun, Moon, and Earth are lined up on the same side meaning gravity pulls in the same direction. Think of a tug of war with the Earth in the middle and only one side has a team pulling!

Neap TidesNeap tides happen 2 times a month, one at first

quarter moon & one at third quarter moon.

The Sun, Earth, and Moon form are at right angles and creates tides with the least intense difference between high & low. So HIGH tides are at their lowest and low tides are at their HIGHEST. (It’s like a tug-of-war between the moon and sun).

Draw It Neap Tides the Sun’s pull is at a right angle

to the Moon’s pull. They pull with similar force causing the higher low tides and lamest, lowest high tides. So the tides are similar in height, not much difference between them.

Motion of Ocean The moon’s gravity pulls more strongly on the side of the

Earth closest to the moon. This causes high tides

The moon’s gravity pulls more weakly on the water on the far side of the moon causing low tides. As the earth rotates the area with high and low tide changes. There are usually two high tides and two low tides each day.

Low tide High Tide

Low Tide

The Tide CycleThe sun is much larger than the moon a baseball

compared to a penny! The sun’s gravity affects the tides.

The little moon affects the tides more because it is closer to the Earth and pulls more on the ocean waves.

Tides are causes mainly by differences in how much gravity from the moon and the sun pulls on different parts of Earth

All tides rotate in a cycle.

What are tides Tides are bulges of water caused by the

difference in the pull of gravity.

This pull depends on the position of Earth, Moon, and Sun