the moon the moon’s light. the sun’s light is reflected off of the moon’s surface. the...

The Moon

The moon’s light.

The sun’s light is reflected off of the moon’s surface.

The different colors on the moon’s surface are caused by the different types of bedrock/regolith.

The Apparent ChangePercentage of illumination – revolution.

Size changes --- shape of the moons orbit.–Large apparent diameter------closer to

Earth–Smaller Apparent diameter—farther

from Earth

Moon Phase Names

• 1 = New Moon

• 2 = First Crescent

• 3 = First Quarter

• 4 = First Gibbous

• 5 = Full Moon

• 6 = Last Gibbous

• 7 = Last Quarter

• 8 = Last Crescent

Sun 1

2

34

5

6

7

8

Earth

Full Moon

First Quarter

Last Gibbous

First Crescent

Lunar Cycle- New Moon to New Moon

29 ½ days

Q: Why do we always see the same side of the moon?

A: Because it rotates at the same rate it revolves. (Pg 15 ESRT)

Q: Why is the period of revolution of the moon 27 1/3 days and the lunar month is 29 ½ days?

Because the Earth is revolving around the Sun at the same time that the Moon is revolving around

the Earth.

https://www.youtube.com/watch?v=nXseTWTZlks

https://www.youtube.com/watch?v=ssA7Ew_BQHY

https://www.youtube.com/watch?v=LaqrQyTm9B4

https://www.youtube.com/watch?v=nXseTWTZlks

– F = force

– G = gravitational constant

– m = mass of object

– r = distance between them

As the distance between two objects doubles, the gravitation force reduces exponentially

𝐹= 𝐺𝑚1𝑚2𝑟2

r = 1 r = 2

𝐹= 𝐺𝑚1𝑚2𝑟2 = ሺ1ሻሺ1ሻ(1)(1) = 1

r = 1 r = 2

𝐹= 𝐺𝑚1𝑚2𝑟2 = ሺ1ሻሺ1ሻ(1)(2)2 = 14

Eclipses• Solar Eclipse

–The moon casts a shadow on the earth.

–Phase of Moon- New Moon

Solar Eclipse

Solar Eclipse from Mir

Christmas Partial Solar Eclipse 2000

Eclipses• Lunar Eclipse

–The earth casts its shadow on the moon

–Phase of moon- Full Moon

Eclipses

• Why eclipses don’t occur every month

• Because the moon’s plane of orbit is on a 5 degree tilt with respect to the Earth’s plane of orbit.

• The moon’s shadow does not reach Earth’s surface when it is at apogee

Lunar Eclipse

Tides• Gravity

– The force of attraction between two masses

– Gravity is directly related to the mass of two objects and the distance between them.

𝐹= 𝐺𝑚1𝑚2𝑟2

•Water on the face of the Earth is pulled by the moon and the Sun.

•The Earth’s rotation causes this force to move the oceans like a large wobbling plate.

•This oscillation causes the water level to periodically rise and fall.

•This is called tides.

•Tides vary from place to place.

•Tides can range from one foot to forty feet every 6 hours.

•The bay of Fundy has forty foot tides.

Tides• Cause of tides

– Water on the surface of the Earth has mass.– The moon’s gravitational force pulls on the

water.– The sun also pulls on the oceans but it is farther

away so its influence is less.

– If the Earth had no moon would we still have tides?

•As the moon orbits the Earth it causes the Average tides to change.

•During a full and new moon the high tides are higher and the low tides are lower.

•During the quarter moon high tides are lower and low tides are higher

Spring Tides at New Moon

SunEarth

New Moon

Higher high tides, lower low tides.

Neap Tides at Quarter Moon

Sun

Earth

Quarter Moon

Higher low tides, lower high tides.