Ch. 28 Sec. 3Ch. 28 Sec. 3

Sun-Moon-Earth SystemSun-Moon-Earth System

Daily MotionsDaily Motions

Sun gives us warmth and energySun gives us warmth and energy Moon rises our oceans and illuminates our Moon rises our oceans and illuminates our

skysky– Ancient calendars are based on moon and sun Ancient calendars are based on moon and sun

phasesphases

Annual MotionsAnnual Motions

Days and weather vary through out the yearDays and weather vary through out the year Annual changes from orbit around the sunAnnual changes from orbit around the sun Ecliptic: Ecliptic: plane in which the earth orbits the sunplane in which the earth orbits the sun

Earth’s TiltEarth’s Tilt

Tilted at 23.5 degreesTilted at 23.5 degrees Axis tilt remains same all yearAxis tilt remains same all year

– This shows how the sun changes altitude in the skyThis shows how the sun changes altitude in the sky– Season are based on the tiltSeason are based on the tilt

SolsticesSolstices Summer SolsticeSummer Solstice

– Sun overhead the Tropic of CancerSun overhead the Tropic of Cancer– Around June 21 or 22 of each yearAround June 21 or 22 of each year– Sun does not set in Arctic circleSun does not set in Arctic circle

SolsticesSolstices

WinterWinter– Sun directly over the Tropic of CapricornSun directly over the Tropic of Capricorn– Occurs on Dec. 21 or 22 Occurs on Dec. 21 or 22 – Sun never rises in the Arctic CircleSun never rises in the Arctic Circle

EquinoxesEquinoxes

Both have equal sunlightBoth have equal sunlight Vernal and AutumnalVernal and Autumnal

Phase of the MoonPhase of the Moon

Light is from the reflection of the sunLight is from the reflection of the sun As moon moves along it’s orbit, the As moon moves along it’s orbit, the

amount of light we see increaseamount of light we see increase Dark Moon positioned between earth and Dark Moon positioned between earth and

sun is New moonsun is New moon

Phase of the MoonPhase of the Moon

Waxing: light that we can see is on the Waxing: light that we can see is on the right side of the moon starts to increaseright side of the moon starts to increase– Crescent – Less that half light is showingCrescent – Less that half light is showing– Gibbous – More than half light is showingGibbous – More than half light is showing

Half of the moon is light: 1Half of the moon is light: 1stst quarter quarter

Phase of the MoonPhase of the Moon

Full moon: entire side is light: Full moonFull moon: entire side is light: Full moon Waning: Light starts to decrease on the Waning: Light starts to decrease on the

left side of the moonleft side of the moon Half the moon is light: 3Half the moon is light: 3rdrd quarter quarter

Motions of the MoonMotions of the Moon Time between full moons is known as the Time between full moons is known as the

Lunar MonthLunar Month– About 29.5 daysAbout 29.5 days– Rises and sets 50 minutes later each day b/c Rises and sets 50 minutes later each day b/c

moon moved 13moon moved 13oo in orbit over 24 hr period in orbit over 24 hr period

TidesTides

Moon pulls up on the ocean and slingshots Moon pulls up on the ocean and slingshots the water on the opposite side to create the water on the opposite side to create bulgesbulges

Every 12 hrs the ocean level rises and fallsEvery 12 hrs the ocean level rises and falls

Solar EclipseSolar Eclipse

Moon passes between sun and earthMoon passes between sun and earth Shadow in the inner/ darker portion is Shadow in the inner/ darker portion is

called the Umbracalled the Umbra Outer/lighter shadow is the PenumbraOuter/lighter shadow is the Penumbra

Effects of orbitsEffects of orbits

Due to the difference in orbit keeps us Due to the difference in orbit keeps us from have an eclipse every month.from have an eclipse every month.

Closest point that moon and earth are is Closest point that moon and earth are is PerigeePerigee– Appears largerAppears larger

Farthest point is the Farthest point is the ApogeeApogee– Appears smallerAppears smaller

Lunar EclipseLunar Eclipse

Moon passes through earths ShadowMoon passes through earths Shadow