FACILITATORGUIDE
SolarEclipse
Learningobjectives
Thisactivityexploresthefollowingideas:
• AsolareclipseoccurswhentheMoonmovesbetweentheSunandEarth,castingashadowon
Earth.
• Asolareclipseisarareandbeautifulevent.
• Peoplehaveobservedandtriedtoexplainsolareclipsesforthousandsofyears.
Materials
• Earthshapedbeachball
• Moontoyonastick
• Pump
• Cone
• Optional:Flashlight(ifdoingtheactivityindoors)
• SizinguptheSun,Earth,andMooninformationsheet
• Activityandfacilitatorguides
TheExploreSciencetoolkitcomescompletewithallnecessarymaterialsforthisactivity.Materials
arealsoreadilyavailabletocreateorrestockactivitykits.Theballsusedinthisactivityareavailable
onlineoratdiscountstores.Graphicfilescanbedownloadedfromwww.nisenet.org.
Notestothepresenter
BesureyourEarthbeachballisfullyinflatedbeforedoingthisactivity.
ThisactivityworkswelloutsidewiththeactualSunasthelightsource.Ifit’scloudyoryouneedtobe
inside,afocusableflashlightcanreplacetheSun.Settheactivityupinadimareaofyourinstitution,or
turnlightsdownlow.
WhileyoucanplacetheEarthballontheconeonthetableandhaveparticipantswalktheMoonaway,
visitorswillbenefitfromthehelpofafriendinthisactivity.Encourageguestswhoarrivealonetowork
withanotherperson.Thetwopeoplecantaketurnsholdingthedifferentballsandpositioningthe
MoonbetweenthelightandEarth.
Theconceptsinthisactivityareappropriateforallages.Evenyoungerparticipantsmayhave
experiencedapartialorcompletesolarorlunareclipse.Allowvisitorstoexperimentwiththedistance
betweentheMoonballandtheEarth—andthelightsourceifyou’reusingaflashlight!Youcanalso
playwithfocusingtheflashlightindifferentwaystogetacrispershadow.
Additionalmaterialsandresourcesrelatedtothe2017solareclipseareavailableintheEventPlanning
andPromotionalGuideandintheEclipsePlanningmini-kitincludedinthetoolkit.Thisresource
packageisalsoavailablefordownloadfromwww.nisenet.org.
Importantnote:TheballsinthisactivityareNOTtoscaleanddonotrepresentanaccuratesizeor
distancecomparisonbetweentheMoon,Earth,andSun.
Difficultconcepts
Withthisactivity,it’simportanttoreinforcethefactthattheseobjectsarejustmodelsfortheSun,
Earth,andMoon.TheyareNOTtoscale.TheSun’sdiameteris400timeswiderthantheMoon’s,and
itisalsomuch,muchlargerintermsofvolumeandmass.Inreallife,theSunis1,392,000kmacross.
TheEarthis12,742kmacross.TheMoonis3,474kmacross.Youcanusetheinformationsheetinthis
activitytohelppeopleconstructamoreaccuaratesenseofthescaleoftheSun,Earth,andMoon.
SeeingatotaleclipsefromEarthisanunusualcoincidence.NotonlydotheSun,Earth,andMoonall
havetolineup,butthesimilarapparentsizeoftheSunandtheMoonallowtheMoon’sshadowto
blocktheSun.TheMoonandSunshareasimilarapparentsizeonlyatthisparticularmomentin
history.Overtime,theMoon’sorbitaroundtheEarthwillcontinuetogetbiggerandbigger,andthe
Moonwillslowlyappearsmallerandsmaller.TheEarth’sdistancefromtheSunisrelativelymore
static.
Evenwhenallthreebodiesareinalignment,wedon’talwaysseeatotalsolareclipse.TheMoonhas
anellipticalorbit,sotheMoon’sdistancefromEarthvariesslightlyoverthecourseofasinglemonth.
TheMoon’sapparentsizeinourskyisalwayschanging.IfaneclipsehappenswhentheMoonisatits
farthestpointawayfromtheEarthinitsorbit,itdoesn’tlookbigenoughtoblocktheSun—thisis
calledanannulareclipse.
Stafftrainingresources
RefertotheTipsforLeadingHands-onActivitiessheetinyouractivitymaterials.
•
Anactivitytrainingvideoisavailableatvimeo.com/191168397.
•
Acontenttrainingvideoisavailableatvimeo.com/191171673.
TheNISENetworkhasacuratedlistofprograms,media,andprofessionaldevelopmentresourcesin
theNASAWavelengthDigitalLibrarythatdirectlyrelatetothetoolkit.Theseresourcescanbeviewed
anddownloadedfromnasawavelength.org/users/nisenet.
Creditsandrights
Versionsofthisactivityexistinmanyforms.ThisactivitywasinspiredbytheDIYSunScienceBigSun,
SmallMoonactivity,developedbyLawrenceHallofScience,UCBerkeley.Retrievedfrom:
http://static.lawrencehallofscience.org/diy_sun_science/downloads/diy_ss_bigsun_smallmoon.pdf
ImageoftheMoon’sshadowonEarthduringthe2016solareclipsecourtesyNASA.
ImageofsunduringasolareclipsecourtesyNASA/Cirtain.
ImageofSunandsolarflarescourtesyNASA.
ImageofEarthcourtesyNASA.
IllustratedsilhouetteofchildbyEmilyMaletzfortheNISENetwork.
DevelopedanddistributedbytheNationalInformalSTEMEducationNetwork.
Copyright2016,ScienceMuseumofMinnesota.PublishedunderaCreative
CommonsAttribution-Noncommercial-ShareAlikelicense:
http://creativecommons.org/licenses/by-nc-sa/3.0/us/
ThismaterialisbaseduponworksupportedbyNASAundercooperativeagreement
awardnumberNNX16AC67A.Anyopinions,findings,andconclusionsorrecommendationsexpressed
inthismaterialarethoseoftheauthor(s)anddonotnecessarilyreflecttheviewoftheNational
AeronauticsandSpaceAdministration(NASA).