The moonThe moon

An intensive look at the An intensive look at the biggest satellite orbiting the biggest satellite orbiting the

earthearth

General InformationGeneral Information

The moon is a satellite because it orbits The moon is a satellite because it orbits the Earththe Earth

Force of gravity is lighter, due to the fact Force of gravity is lighter, due to the fact that it is a lighter body than the earththat it is a lighter body than the earth• 6:1 ratio – if you weigh 120lb on earth, you 6:1 ratio – if you weigh 120lb on earth, you

only weigh 20 lbs on the moononly weigh 20 lbs on the moon No atmosphereNo atmosphere Temperature range from 134Temperature range from 134-170-170 Orbits every 29.5 daysOrbits every 29.5 days

Lunar SurfaceLunar Surface

Light and dark patchesLight and dark patches Dark areas are known as “maria” Dark areas are known as “maria”

mar= sea in Latinmar= sea in Latin• Space Scientists used to think they were Space Scientists used to think they were

seasseas• Now they know it is dark solidified lavaNow they know it is dark solidified lava

Long, deep channels – known as Long, deep channels – known as RillesRilles

Lunar Surface continuedLunar Surface continued

Lunar Highlands- light areas of moon; Lunar Highlands- light areas of moon; contain 2 types of rockscontain 2 types of rocks

Regolith- lunar soil (loose rock) Regolith- lunar soil (loose rock) formed from smashing meteoroids formed from smashing meteoroids (celestial body range of size).(celestial body range of size).

CratersCraters

Most formed 4 billion years agoMost formed 4 billion years ago Caused by meteorsCaused by meteors Debris known as raysDebris known as rays Earth is believed to once have Earth is believed to once have

craters similar to those on the mooncraters similar to those on the moon

Lunar orbit and rotationLunar orbit and rotation

The orbit of the moon around the The orbit of the moon around the earth forms an ellipse, not a circleearth forms an ellipse, not a circle• Distance of moon to earth variesDistance of moon to earth varies

When the moon is farthest – it is When the moon is farthest – it is ApogeeApogee When the moon is closest – it is When the moon is closest – it is PerigeePerigee

Same side of the moon is always Same side of the moon is always facing us. facing us.

Why do we only see the same side Why do we only see the same side of the moonof the moon

““Tidal forces between Earth and the Moon have slowed the moon's rotation so that the same side is always facing the Earth. The other face, which is never visible from the Earth in its entirety (18% is seen, see Tidal locking), is therefore called the "far side of the Moon".””

EclipsesEclipses

Occurs when one planetary body Occurs when one planetary body passes through the shadow of passes through the shadow of anotheranother

Shadow of any solid object has 2 Shadow of any solid object has 2 parts:parts:• UmbraUmbra- sunlight completely blocked - sunlight completely blocked

(inner-cone shaped)(inner-cone shaped)• PenumbraPenumbra- sunlight partially blocked- sunlight partially blocked

Lunar EclipsesLunar Eclipses

Lunar Eclipse Lunar Eclipse – when the earth is – when the earth is positioned between the moon and positioned between the moon and the sun, and the earth’s shadow the sun, and the earth’s shadow crosses the lighted half of the moon crosses the lighted half of the moon (fully in Earth’s umbra)(fully in Earth’s umbra)

Partial lunar eclipse- moon only Partial lunar eclipse- moon only partly in earth’s umbrapartly in earth’s umbra

Total lunar eclipse- moon fully in Total lunar eclipse- moon fully in earth’s umbraearth’s umbra

Lunar EclipseLunar Eclipse

Solar eclipsesSolar eclipses Solar Eclipse Solar Eclipse – when the shadow of the – when the shadow of the

moon falls on the earth, occurs only at the moon falls on the earth, occurs only at the new moon phase. Moon’s small umbra makes new moon phase. Moon’s small umbra makes it rare.it rare.

Annular solar eclipse- occurs at apogee Annular solar eclipse- occurs at apogee (moon farthest), umbra falls short, we (moon farthest), umbra falls short, we see the outermost circle of sun.see the outermost circle of sun.

Total solar eclipse- moon at perigee, Total solar eclipse- moon at perigee, umbra reaches earth, completely blocks umbra reaches earth, completely blocks out sun.out sun.

Annular Solar EclipseAnnular Solar Eclipse

Total Solar EclipseTotal Solar Eclipse

Moon phasesMoon phases

New MoonNew Moon Waxing crescentWaxing crescent First QuarterFirst Quarter Waxing gibbousWaxing gibbous Full MoonFull Moon Waning gibbousWaning gibbous Last QuarterLast Quarter Waning crescentWaning crescent

WaxingWaxing

When the size of the visible portion When the size of the visible portion of the moon is increasing of the moon is increasing

New MoonNew Moon

No lighted area of the moonNo lighted area of the moon

Waxing (New) CrescentWaxing (New) Crescent

Only a sliver of the moon is visible on Only a sliver of the moon is visible on the right.the right.

First Quarter (Half Moon)First Quarter (Half Moon)

Only a quarter ( we see it as half) of Only a quarter ( we see it as half) of the moon is visible from the right.the moon is visible from the right.

Waxing GibbousWaxing Gibbous More than half, but less than full of More than half, but less than full of

the moon is visible from the right. the moon is visible from the right. (3/4 visible)(3/4 visible)

Last phase before full moon.Last phase before full moon.

WaningWaning

The portion of the moon visible from The portion of the moon visible from earth is decreasingearth is decreasing

Full MoonFull Moon

When the moon appears in full circleWhen the moon appears in full circle The earth is between the sun and the The earth is between the sun and the

moonmoon

Waning GibbousWaning Gibbous

More than half, but less than full of More than half, but less than full of the moon is visible from the left. (3/4 the moon is visible from the left. (3/4 visible)visible)

Last QuarterLast Quarter

Only a quarter ( we see it as half) of Only a quarter ( we see it as half) of the moon is visible from the left.the moon is visible from the left.

Waning (Old) CrescentWaning (Old) Crescent

Only a sliver of the moon is visible Only a sliver of the moon is visible from the left.from the left.

Last phase before New moon Last phase before New moon appears again.appears again.