The MoonThe Moon

Many of the Many of the discoveries on the discoveries on the moon were made moon were made

possible as a result of possible as a result of the Russian-American the Russian-American

Space RaceSpace Race

The later Apollo The later Apollo missions were missions were dedicated to dedicated to

understanding more understanding more about the moon itself about the moon itself

and its origin.and its origin.

Go Go herehere for a more for a more detailed description of detailed description of

lunar missions.lunar missions.

There are several There are several theories concerning the theories concerning the originorigin of the moon. The of the moon. The

most accepted most accepted Impact Theory Impact Theory says that says that the moon was formed as the moon was formed as a result of a Mars-sized a result of a Mars-sized

meteor crashing into the meteor crashing into the Earth.Earth.

Because the moon has no Because the moon has no atmosphere, atmosphere, meteoroidsmeteoroids

ranging in size from a ranging in size from a speck to an object speck to an object

weighing thousands of weighing thousands of kilograms have been kilograms have been

crashing into the moon crashing into the moon for many years.for many years.

Evidence of these Evidence of these collisions are large collisions are large

craterscraters on the moon’s on the moon’s surface.surface.

The moon is still being The moon is still being bombarded by bombarded by

micrometeoroidsmicrometeoroids today.today.

Many large boulders Many large boulders and large mountains and large mountains occupy the surface.occupy the surface.

Moon/Earth PropertiesMoon/Earth PropertiesProperty Moon Earth

Mass 0.07349 X 1024 kg 5.9736 X 1024 kg

Radius 1738.1 km 6378.1 km

Period of Revolution 27.3 days 365.26 days

Period of Rotation 27.3 days 24 hours

Accel. Due to Gravity (g)

1.6 m/s2 9.8 m/s2

Distance from Sun 0.386 million km from Earth

149.6 million km

You can jump a lot higher You can jump a lot higher on the moon. The gravity is on the moon. The gravity is

1/61/6thth what it is here on what it is here on Earth!Earth!

If the gravity is 1/6If the gravity is 1/6thth what it what it is here on Earth, how high is here on Earth, how high

would Magic Johnson jump?would Magic Johnson jump?

BrainteaserBrainteaser: Newton’s : Newton’s second law of motion states second law of motion states that Force (weight) = mass X that Force (weight) = mass X

gravitational acceleration. gravitational acceleration. Does your weight change Does your weight change when going to the moon? when going to the moon? Does your mass change Does your mass change

when going to the moon?when going to the moon?

Answer:Answer: Weight changes, Weight changes, mass does not!mass does not!

Question:Question: How much would How much would you you weighweigh on the moon? on the moon?

How much would your How much would your massmass be on the moon?be on the moon?

Answer: Answer: Consider that the Consider that the gravity on the moon is 1/6gravity on the moon is 1/6thth what it is here on Earth. Do what it is here on Earth. Do

the math!the math!

Lunar Lunar MariaMaria: large flat : large flat basinsbasins

Lunar Highlands surround Lunar Highlands surround MariaMaria

Lunar Rays radiate out Lunar Rays radiate out from cratersfrom craters

Lunar rocks and soil Lunar rocks and soil (regolith)(regolith)

Volcanic Basalt (Igneous extrusive rock Volcanic Basalt (Igneous extrusive rock formed from volcanic eruptions. Similar to formed from volcanic eruptions. Similar to

rock found in Hawaii)rock found in Hawaii)

Igneous Intrusive Anorthosite (AKA: Igneous Intrusive Anorthosite (AKA: Genesis Rock, the original crust of the Genesis Rock, the original crust of the

Moon!)Moon!)

Volcanic Breccia (formed when asteroid Volcanic Breccia (formed when asteroid impact melts rock and then the rock re-impact melts rock and then the rock re-

crystallizes)crystallizes)

Volcanic Soil (regolith): formed when Volcanic Soil (regolith): formed when meteoroids pulverize lunar rocksmeteoroids pulverize lunar rocks

Moon rocks have been Moon rocks have been dated to be around the dated to be around the

same age as some of the same age as some of the oldest Earth rocks, oldest Earth rocks,

leading to the idea that leading to the idea that the moon is actually a the moon is actually a

part of the Earth that was part of the Earth that was broken off by a meteor broken off by a meteor

impact.impact.

The Moon’s MotionsThe Moon’s Motions

The Moon takes 27.3 The Moon takes 27.3 days to go around the days to go around the

Earth. It’s orbit is Earth. It’s orbit is elliptical and has an elliptical and has an average distance of average distance of

384,000 km.384,000 km.Perigee = closest to earth

Earth Apogee = farthest from earth

The moon will rise and The moon will rise and set 50 minutes later each set 50 minutes later each

day/night. If the moon day/night. If the moon rises at 9:00 tonight, rises at 9:00 tonight, what time will it rise what time will it rise

tomorrow night?tomorrow night?

PhasesPhases are daily changes are daily changes in appearance as viewed in appearance as viewed from earth. The moon is from earth. The moon is

waxingwaxing when it is when it is between new and full between new and full

phase. It is phase. It is waningwaning when when it is between full and new it is between full and new

phase.phase.

GibbousGibbous is when almost is when almost all of the bright side is all of the bright side is facing us. facing us. CrescentCrescent is is

when only a little sliver of when only a little sliver of the bright side is facing the bright side is facing

us.us.

Moon PhasesMoon Phases

A A lunar eclipselunar eclipse is when is when the Earth comes in the Earth comes in

between the sun and between the sun and moon.moon.

A solar eclipse is when A solar eclipse is when the moon comes in the moon comes in

between the Earth and between the Earth and Sun.Sun.

In an eclipse, In an eclipse, umbraumbra is is the area of total shadow. the area of total shadow. PenumbraPenumbra is the area of is the area of

partial shadow.partial shadow.

Ocean Ocean TidesTides are the are the periodic rise and fall of periodic rise and fall of

the ocean surface due to the ocean surface due to the gravitational pulls of the gravitational pulls of the moon and sun. Go the moon and sun. Go

here to learn more about here to learn more about tides.tides.

Both the moon and sun Both the moon and sun have an effect on our have an effect on our

tides. Which one do you tides. Which one do you think has the greater think has the greater

effect?effect?

If you said the moon, you If you said the moon, you would be correct! The would be correct! The

moon is much less moon is much less massive than the sun, but massive than the sun, but

it is much closer. The it is much closer. The sun’s tide making effect sun’s tide making effect is only about ½ that of is only about ½ that of

the moon.the moon.

There are 2 types of There are 2 types of tides, spring tides and tides, spring tides and neap tides. Go here for neap tides. Go here for

animation.animation.

Spring TidesSpring Tides occur when the occur when the sun, earth, and moon are sun, earth, and moon are lined up in a straight line. lined up in a straight line.

They are the strongest and They are the strongest and coincide with the full or new coincide with the full or new

moon.moon.

Neap TidesNeap Tides occur when the occur when the sun, earth, and moon are at sun, earth, and moon are at right angles to each other. right angles to each other. They are the weakest and They are the weakest and

coincide with the first coincide with the first quarter or third quarter.quarter or third quarter.

Tidal influence is greatest Tidal influence is greatest at at perigeeperigee and weakest and weakest

at at apogeeapogee..

Perigee = closest to earth

Earth Apogee = farthest from earth

Tides can vary throughout the Tides can vary throughout the day and can depend on the day and can depend on the

local area. The Bay of Fundy in local area. The Bay of Fundy in Canada is a great example.Canada is a great example.