, ACCESS Test Bank for Explorations 10th Edition Arny
m m m m m m m
Chapterm1 ThemCyclesmof mthemSky
CHAPTER m1mTHEmCYCLESmOFmTHEmSKY
LecturemSuggestions
Planetariummsoftwaremmaymbemhelpfulmformthismchapter.mAnmorrerym(mechanicalmmodelmof mt
hemSunmand mEarth)mormevenmjust manmapproximationmof monemcanmalsomhelpmillustratemvariousm motion
smand mthat mthemconstellationsmchangemwithmthemseasons.mSet mit monmamtableminmthemfront mof mthemroomm
and mthenmmarkmoff mconstellationsmonmthemwallsmwithmchalkmormpapermdecorations.mMovingmthemmo
delmEarthmaround mthemmodelmSunmthenmallowsmstudentsmtomseemhow mthemstarsmvisiblymchangemand mh
owmthemSunm“moves”mthroughmthemZodiac.mInmeffect,mthismturnsmthemroommintomamsimplemplanetariu
m.
A mflashlight mwithmamfat mbeammshowsmthemimportancemof manglemtomseasonalmheating.mWhenm
directed mdirectlymat mthemwallmthemenergymismconcentrated minmamsmallmarea.mWhenmshined mobliquelym
at mthemwall,mthembeammcoversmamlargermarea,mimplyingmlessmconcentrationmof mheat mand mthereforemaml
owermtemperature.mIt’smalsomimportant mtomincludemthemideamthat mthemdaymismlongerminmthemsummer,m
whichmismsometimesmoverlooked.
A mbright mlight msourcemand mtennismballs,mbasketballs,mvolleyballsmormevenmgolf mballsmcanmde
monstratemfeaturesmof meclipsesmand mphasesmof mthemmoon.
AnswersmtomThought mQuestions
1. If myoumweremstandingmonmEarth’smequator,mlookingmduemnorthmyoumwould mseemthemnorthmcelest
ialmpolemonmthemhorizonm(and mthemsouthmcelestialmpolemonmthemhorizon, mlookingmduemsouth).Y
oumcannot mseemthemnorthmcelestialmpolemfrommAustraliam(it’smbelow mthemhorizon),monlymthemso
uthmcelestialmpole.
2. SKETCH mFORmSTUDENTS
3. Themmainmastronomicalmreasonmwhymtheremarem12mzodiacalmsignsmismthat mthemSunmappears
mtommovemabout m30mdegreesmpermmonthmacrossmthembackground mstarsm (360m/m30m=12)m.
4. SKETCH mFORmSTUDENTS.mAt mthemhorizon,msettingmormrisingmstarsmmovemperpendicularlymt
omthemhorizonm(somtheymaremusefulmformEast-
West mnavigation).mAt mthemnorthmpole,mstarsmmoremormlessmdomnot mset,mtheymjust mcircleminmthemsk
y.mAt mammid-
latitude,mthemstarsmmakemanmanglemwithmthemhorizon.mInmthemNorthernmHemisphere,masmtheymset m
theymalsommovemmoremtoward mthemnorth.mExtremelymschematically:msettingmstarsmlookingmwest:
mat mthemequator,m|m|m|;mat mammid-latitude,mNorthernmHemisphere:m\m\m\;mat mthemNorthmPole,m---.
5. Whenmit mismwinterminmNew mYork,mthemNorthernmHemispheremismtilted mawaymfrommthemSun;mther
eforemat mthat mtimemthemSouthernmHemispheremismtilted mtowardsmthemSunmand mit’smsummerminmA
ustralia.mAlthoughmBeijingmismpartwaymaround mthemworld mfrommNew mYork,mit’sminmthemNorther
nmHemispheremand mit mismalsomwintermthere.mThempart mof mthemskymthat myoumseemat mnight mismthempa
rt mof mthemskymawaymfrommthemSun,msomeverywheremonmEarthmseesmthemsamem“half”mof mthemskyma
t mnight mduringmam24mhourmperiod,masmEarthmrotatesmviewersmintomnighttime:mallmthreemlocationsm
should mbemablemtomseemOrion,mwhichmstraddlesmthemcelestialmequator.
6. If mEarth’smorbit mhad mnomtilt,mtheremwould mbemnomvariationminmthemanglemof msunlight movermthemy
1
©mMcGrawmHillmLLC.mAllmrights mreserved.mNo mreproductionmormdistributionmwithoutmthemprior mwrittenmconsentmof mMcGrawm
HillmLLC.
mynursytest.store
,ear,mnormwould mtherembemvariationminmthemlengthmof mday—
conditionsmwould mbemsomewhat mlikemthe
2
©mMcGrawmHillmLLC.mAllmrights mreserved.mNo mreproductionmormdistributionmwithoutmthemprior mwrittenmconsentmof mMcGrawm
HillmLLC.
mynursytest.store
, ACCESS Test Bank for Explorations 10th Edition Arny
m m m m m m m
Chapterm1 ThemCyclesmof mthemSky
equinoxmallmthemtimemand mam12mhourmdaymeverywhere,meverymday.mTheremwould mbemamslight mvar
iationminmtemperaturemovermthemyearmwithmhighermtemperaturesminmJanuarymbased monmthemsmallm
changeminmEarth’smdistancemfrommthemSun,mbut mthismeffect mwould mbemverymsmallm(clearlymit mdoe
smnot maffect mthemseasonsminduced mbymthemtilt mverymmuch).mNorthernmand mSouthernmhemispheres
mwould mexperiencemthesemweakmseasonsmat mthemsamemtime.
7. Thempositionmof msunrisemalongmthemeasternmhorizonmchangesmduringmthemyearmbecausemEarth’sm
axism(and mcorrespondingly,mthemcelestialmequator)mismtilted mat m23.5mdegreesmtomthemplanemof mitsm
orbit m(themecliptic)mand mEarthmmaintainsmthismsamemtilt mthroughout mthemyear.mAt mthemequinoxes
m(Marchm21mand mSept.m23),mthemSunmliesmonmthemcelestialmequator.mBecausemthemcelestialmequat
ormcutsmthemhorizonmat mthemeast mand mwest mpoints,mthemSunmwillmrisemand mset mduemeast mand mduem
west,mrespectively.mInmwinter,mthemtilt mof mEarthmresultsminmthemSunmrisingmnorthmof meast mand msett
ingmnorthmof mwest,mand minmwinter,mthemSunmrisingmsouthmof meast mand msettingmsouthmof mwest.mAt m
themwintermsolsticem(Dec.m21),mthemSunmliesm23.5mdegreesmsouthmof mthemcelestialmequatormonmthe
msky.mIt mwillmthereforemrisemthemmost mtomthemsouthmof mthemEast monmthemhorizonmand mset mthemmost
mtomthemsouthmof mWest mthat myear.mAt mthemsummermsolsticem(Junem21),mthemSunmliesm23.5mdegree
smnorthmof mthemcelestialmequator.mIt mwillmthereforemrisemthemmost mnorthmof mEast mand mset mthemmos
t mNorthmof mWest.
8. Wemhavemtimemzonesmtomkeepmourmlocalmtimeminmapproximatemalignment mwithmsolar mtime,mand m
tomstandardizemtimembetweenmdifferent mpartsmof mcountriesmand mthemworld—
usingmexact mlocalmsolarmtimemeverywheremwould mbemjust masmconfusing masmusingmonem set mof mhou
rsmformthemwholemworld.mThemsketchmcanmshow mhowmit’smsolarmnoonmonmonempart mof mearthm(them
Sunmismhighest minmthemsky)mand mamverymdifferent mtimemelsewherem(themSunmwould mbemhighmorml
owminmthemsky),mormjust mshowmamclose-
upmof mthemdifferencembetweenmthemlocalmtimeminmonemtimemzonem(saymnoon)mand manmadjacent mti
memzonem(saym1mpm).
9. Somempossiblemideas:m(Onemormtwomof mthesemormrelated mideasmshould mbemsufficient).
– Youmcanmseemsomemphasesmduringmthemday,msomthemgeometrymismincorrect mformthemphasemto
mbemamshadow.
– YoumcanmdeterminemthemSun-Earth-Moonmanglemismnot m180mdegreesmduringmmost mphases.
– Lunarmeclipsesm(shadow monmthemMoon)mdomoccur,mandmonlymduringmthem180mdegree/f
ullmmoonmalignment.
– Themcurvaturemof mthemterminatormduringmMoonmphasesmismnot mconsistent mfrommphase
mtomphase—
if mit mwasmEarth’smshadow,mit mwould malwaysmbemthemsamemshape.m Themchangingmtermi
natormshapemismconsistent mwithmampartiallymilluminated msphere.
– Themradiusmof mcurvaturemof mthemterminatormformphasesmdoesmnot mmatchmthemradiusmof mt
hemshadow mof mEarthmduringmanmeclipse.
– Eclipsesmhappenmovermamperiod mof mhours,mwhilemthemphasesmchangemslowlymovermwee
ks,msuggestingmtheymaremnot mcaused mbymthemsamemthing.
10. Inmthismcase,mthemsiderealmmonthmwould mremainm27.3mdaysmasmthemperiodicmalignment mwithmt
hemstarsmwould mnot mchange,mbut mthemsolarmmonthmwould mbemshortermbecausemthemMoonmwillm
reachmnew mmoonmbeforemre-
aligningmwithmthemstarsminstead mof mafter.mThemredrawnmfiguremof m1.14mshould mindicatemthismis
mthemcasem(themright mpart mof mthemdiagrammwillmhappenminmoppositemorder).
3
©mMcGrawmHillmLLC.mAllmrights mreserved.mNo mreproductionmormdistributionmwithoutmthemprior mwrittenmconsentmof mMcGrawm
HillmLLC.
mynursytest.store
m m m m m m m
Chapterm1 ThemCyclesmof mthemSky
CHAPTER m1mTHEmCYCLESmOFmTHEmSKY
LecturemSuggestions
Planetariummsoftwaremmaymbemhelpfulmformthismchapter.mAnmorrerym(mechanicalmmodelmof mt
hemSunmand mEarth)mormevenmjust manmapproximationmof monemcanmalsomhelpmillustratemvariousm motion
smand mthat mthemconstellationsmchangemwithmthemseasons.mSet mit monmamtableminmthemfront mof mthemroomm
and mthenmmarkmoff mconstellationsmonmthemwallsmwithmchalkmormpapermdecorations.mMovingmthemmo
delmEarthmaround mthemmodelmSunmthenmallowsmstudentsmtomseemhow mthemstarsmvisiblymchangemand mh
owmthemSunm“moves”mthroughmthemZodiac.mInmeffect,mthismturnsmthemroommintomamsimplemplanetariu
m.
A mflashlight mwithmamfat mbeammshowsmthemimportancemof manglemtomseasonalmheating.mWhenm
directed mdirectlymat mthemwallmthemenergymismconcentrated minmamsmallmarea.mWhenmshined mobliquelym
at mthemwall,mthembeammcoversmamlargermarea,mimplyingmlessmconcentrationmof mheat mand mthereforemaml
owermtemperature.mIt’smalsomimportant mtomincludemthemideamthat mthemdaymismlongerminmthemsummer,m
whichmismsometimesmoverlooked.
A mbright mlight msourcemand mtennismballs,mbasketballs,mvolleyballsmormevenmgolf mballsmcanmde
monstratemfeaturesmof meclipsesmand mphasesmof mthemmoon.
AnswersmtomThought mQuestions
1. If myoumweremstandingmonmEarth’smequator,mlookingmduemnorthmyoumwould mseemthemnorthmcelest
ialmpolemonmthemhorizonm(and mthemsouthmcelestialmpolemonmthemhorizon, mlookingmduemsouth).Y
oumcannot mseemthemnorthmcelestialmpolemfrommAustraliam(it’smbelow mthemhorizon),monlymthemso
uthmcelestialmpole.
2. SKETCH mFORmSTUDENTS
3. Themmainmastronomicalmreasonmwhymtheremarem12mzodiacalmsignsmismthat mthemSunmappears
mtommovemabout m30mdegreesmpermmonthmacrossmthembackground mstarsm (360m/m30m=12)m.
4. SKETCH mFORmSTUDENTS.mAt mthemhorizon,msettingmormrisingmstarsmmovemperpendicularlymt
omthemhorizonm(somtheymaremusefulmformEast-
West mnavigation).mAt mthemnorthmpole,mstarsmmoremormlessmdomnot mset,mtheymjust mcircleminmthemsk
y.mAt mammid-
latitude,mthemstarsmmakemanmanglemwithmthemhorizon.mInmthemNorthernmHemisphere,masmtheymset m
theymalsommovemmoremtoward mthemnorth.mExtremelymschematically:msettingmstarsmlookingmwest:
mat mthemequator,m|m|m|;mat mammid-latitude,mNorthernmHemisphere:m\m\m\;mat mthemNorthmPole,m---.
5. Whenmit mismwinterminmNew mYork,mthemNorthernmHemispheremismtilted mawaymfrommthemSun;mther
eforemat mthat mtimemthemSouthernmHemispheremismtilted mtowardsmthemSunmand mit’smsummerminmA
ustralia.mAlthoughmBeijingmismpartwaymaround mthemworld mfrommNew mYork,mit’sminmthemNorther
nmHemispheremand mit mismalsomwintermthere.mThempart mof mthemskymthat myoumseemat mnight mismthempa
rt mof mthemskymawaymfrommthemSun,msomeverywheremonmEarthmseesmthemsamem“half”mof mthemskyma
t mnight mduringmam24mhourmperiod,masmEarthmrotatesmviewersmintomnighttime:mallmthreemlocationsm
should mbemablemtomseemOrion,mwhichmstraddlesmthemcelestialmequator.
6. If mEarth’smorbit mhad mnomtilt,mtheremwould mbemnomvariationminmthemanglemof msunlight movermthemy
1
©mMcGrawmHillmLLC.mAllmrights mreserved.mNo mreproductionmormdistributionmwithoutmthemprior mwrittenmconsentmof mMcGrawm
HillmLLC.
mynursytest.store
,ear,mnormwould mtherembemvariationminmthemlengthmof mday—
conditionsmwould mbemsomewhat mlikemthe
2
©mMcGrawmHillmLLC.mAllmrights mreserved.mNo mreproductionmormdistributionmwithoutmthemprior mwrittenmconsentmof mMcGrawm
HillmLLC.
mynursytest.store
, ACCESS Test Bank for Explorations 10th Edition Arny
m m m m m m m
Chapterm1 ThemCyclesmof mthemSky
equinoxmallmthemtimemand mam12mhourmdaymeverywhere,meverymday.mTheremwould mbemamslight mvar
iationminmtemperaturemovermthemyearmwithmhighermtemperaturesminmJanuarymbased monmthemsmallm
changeminmEarth’smdistancemfrommthemSun,mbut mthismeffect mwould mbemverymsmallm(clearlymit mdoe
smnot maffect mthemseasonsminduced mbymthemtilt mverymmuch).mNorthernmand mSouthernmhemispheres
mwould mexperiencemthesemweakmseasonsmat mthemsamemtime.
7. Thempositionmof msunrisemalongmthemeasternmhorizonmchangesmduringmthemyearmbecausemEarth’sm
axism(and mcorrespondingly,mthemcelestialmequator)mismtilted mat m23.5mdegreesmtomthemplanemof mitsm
orbit m(themecliptic)mand mEarthmmaintainsmthismsamemtilt mthroughout mthemyear.mAt mthemequinoxes
m(Marchm21mand mSept.m23),mthemSunmliesmonmthemcelestialmequator.mBecausemthemcelestialmequat
ormcutsmthemhorizonmat mthemeast mand mwest mpoints,mthemSunmwillmrisemand mset mduemeast mand mduem
west,mrespectively.mInmwinter,mthemtilt mof mEarthmresultsminmthemSunmrisingmnorthmof meast mand msett
ingmnorthmof mwest,mand minmwinter,mthemSunmrisingmsouthmof meast mand msettingmsouthmof mwest.mAt m
themwintermsolsticem(Dec.m21),mthemSunmliesm23.5mdegreesmsouthmof mthemcelestialmequatormonmthe
msky.mIt mwillmthereforemrisemthemmost mtomthemsouthmof mthemEast monmthemhorizonmand mset mthemmost
mtomthemsouthmof mWest mthat myear.mAt mthemsummermsolsticem(Junem21),mthemSunmliesm23.5mdegree
smnorthmof mthemcelestialmequator.mIt mwillmthereforemrisemthemmost mnorthmof mEast mand mset mthemmos
t mNorthmof mWest.
8. Wemhavemtimemzonesmtomkeepmourmlocalmtimeminmapproximatemalignment mwithmsolar mtime,mand m
tomstandardizemtimembetweenmdifferent mpartsmof mcountriesmand mthemworld—
usingmexact mlocalmsolarmtimemeverywheremwould mbemjust masmconfusing masmusingmonem set mof mhou
rsmformthemwholemworld.mThemsketchmcanmshow mhowmit’smsolarmnoonmonmonempart mof mearthm(them
Sunmismhighest minmthemsky)mand mamverymdifferent mtimemelsewherem(themSunmwould mbemhighmorml
owminmthemsky),mormjust mshowmamclose-
upmof mthemdifferencembetweenmthemlocalmtimeminmonemtimemzonem(saymnoon)mand manmadjacent mti
memzonem(saym1mpm).
9. Somempossiblemideas:m(Onemormtwomof mthesemormrelated mideasmshould mbemsufficient).
– Youmcanmseemsomemphasesmduringmthemday,msomthemgeometrymismincorrect mformthemphasemto
mbemamshadow.
– YoumcanmdeterminemthemSun-Earth-Moonmanglemismnot m180mdegreesmduringmmost mphases.
– Lunarmeclipsesm(shadow monmthemMoon)mdomoccur,mandmonlymduringmthem180mdegree/f
ullmmoonmalignment.
– Themcurvaturemof mthemterminatormduringmMoonmphasesmismnot mconsistent mfrommphase
mtomphase—
if mit mwasmEarth’smshadow,mit mwould malwaysmbemthemsamemshape.m Themchangingmtermi
natormshapemismconsistent mwithmampartiallymilluminated msphere.
– Themradiusmof mcurvaturemof mthemterminatormformphasesmdoesmnot mmatchmthemradiusmof mt
hemshadow mof mEarthmduringmanmeclipse.
– Eclipsesmhappenmovermamperiod mof mhours,mwhilemthemphasesmchangemslowlymovermwee
ks,msuggestingmtheymaremnot mcaused mbymthemsamemthing.
10. Inmthismcase,mthemsiderealmmonthmwould mremainm27.3mdaysmasmthemperiodicmalignment mwithmt
hemstarsmwould mnot mchange,mbut mthemsolarmmonthmwould mbemshortermbecausemthemMoonmwillm
reachmnew mmoonmbeforemre-
aligningmwithmthemstarsminstead mof mafter.mThemredrawnmfiguremof m1.14mshould mindicatemthismis
mthemcasem(themright mpart mof mthemdiagrammwillmhappenminmoppositemorder).
3
©mMcGrawmHillmLLC.mAllmrights mreserved.mNo mreproductionmormdistributionmwithoutmthemprior mwrittenmconsentmof mMcGrawm
HillmLLC.
mynursytest.store
