PocketSolarSystem–Grade3rd+
PocketSolarSystem
DarkSkies,BrightKids
UniversityofVirginia,DepartmentofAstronomy
P.O.Box400325
Charlottesville,VA22904
dsbk@virginia.edu
ActivityTime:35min
PrepTime:10min
Grade:3rd+
StandardsofLearningTopic
•
PrimarySOL
o Science4.7:Thestudentwillinvestigateandunderstandtheorganizationofthe
solarsystem.Keyconceptsinclude
a) theplanetsinthesolarsystem;
b) theorderoftheplanetsinthesolarsystem;
c) therelativesizesoftheplanets.
Description
Students begin by predicting the locations of the eight planets and Pluto on a piece of
register tape. The students then place stickers at the actual locations of the planets and
compare this to their predictions. Relative locations are determined by folding the register
tape,takingadvantageofthe(roughly)evenratiosbetweenplanetarydistances.Studentscan
begiventheoptionofdecoratingtheirSolarSystemmodel.
Materials
•
•
Teacherneeds
AlternateMaterials
o Scissors
• Planetstickerscanbefoundat
Eachstudentneeds
mosteducationalstores.
o Writingutensils
o Artsupplies
o Cashregistertape(3-4ftperstudent)
o Stickers(atleast10perstudentforthe8planets,theSun,andPluto)
Goals
•
•
•
IllustratetherelativedistancesintheSolarSystem
DemonstratehowlargetheSolarSystemis
ReinforcethenamesandorderofmajorSolarSystembodies
PocketSolarSystem–Grade3rd+
IntroductiontoTopic
The scale of the Solar System is very difficult to
comprehend. Making a scale model emphasizes how
largethedistancesarebetweenSolarSystemobjects.
Pre-ActivityInstruction
This activity works best if the students are already
familiar with the name and order of the planets in the
SolarSystem.
Preparation
ProTips
• Youmaywantthenamesof
theplanets,Sun,andasteroid
beltontheboardtohelp
studentswithspelling.
• Studentscanplacethestickers
tothesideofthecreasesinthe
registertapesotheyarenot
bentwithadditionalfolding.
1) Cutregistertapeinto3-4ftsegments.
2) Giveoutstickers.
Procedure
1) Have students mark the location of the Sun at one end of the tape and Pluto at the
other.Askthemtomarkonthepaperwheretheythinktherestoftheplanetsshouldbe
onthisscale.Simplyplacinganxandlabelingthelocationissufficient.
2) Nowthestudentswillplacestickersatthecorrectlocationsonthepaper.
a. Fold the paper in half, open it back up, and place a sticker at the crease. This is
Uranus.
b. Foldthepaperbackinhalf,theninhalfagain(tomakequarters).Openitbackup
andplaceastickeratthe¼foldclosertotheSun.ThisisSaturn.
c. Placeanotherstickeratthe¾fold.ThisisNeptune.
d. FoldtheSunuptoSaturnandmakeacrease(thisis1/8thofthepaper).Openitback
upandplaceastickeratthenewcreaseforJupiter.
e. Fold the Sun to Jupiter and make a crease (this is 1/16th of the paper). There is
actuallynoplanethere;thisisthecenteroftheasteroidbelt!Studentscanplacea
numberofsmalldotsheretorepresentasteroids.
f. FoldtheSuntotheasteroidbeltandmakeacrease(thisis1/32ndofthepaper).This
isMars.
g. Theremainingplanets(Earth,Venus,andMercury)areallwithintheorbitofMars
anditisnolongerusefultotryandmarkthelocationsbyfolding.Instead,havethe
studentsevenlyspacetheremainingstickerstomarkthelocationoftheinnerthree
planets:Mercury(closesttotheSun),Venus,andEarth.
3) OpenuptheentirepaperandlookattheSolarSystem!Studentscanwritethenames
undertheplanetsandcontinuedecoratingtheirpocketSolarSystem.
4) Havethestudentscomparethereallocationswiththeirpredictions.
Post-ActivityDiscussion
•
ThemostdistantbodythathumanshavevisitedistheMoon.WherewouldtheMoonbe
onthismodel?
PocketSolarSystem–Grade3rd+
•
•
•
•
•
•
TheMoonwouldbeabout1/1000thinchfromtheEarth!Thisisaboutthediameter
ofasinglehumanhair.Ittakeshumans3daystotravelfromtheEarthtotheMoon.
Basedonthis,howlongwouldittaketotraveltotheSun?Jupiter?
While humans have gone no farther than the Moon, we have sent spacecraft to other
locationsintheSolarSystem.TheVoyagerspacecraftleftEarthin1987.Howfardoyou
thinkVoyagerhastraveled?
AsofNovember2012,Voyagerismorethan122astronomicalunitsfromtheSun.
Thatis3timesfartherfromtheSunthanPluto,or3timesthelengthofyourpocket
SolarSystem!
Usingyourmodel,howfarawayistheneareststar?
ProximaCentauriistheclosestknownstartotheSunatadistanceof4.2lightyears.
A light year is the distance that light can travel in 1 year. An astronomical unit is
roughly9lightminutes.Foryourmodel,ProximaCentauriwouldbe3.8milesaway!
Theplanetsinyourmodelarespacedcorrectly,buttheirsizesarenottoscale.Howbig
shouldtheplanetsbeinyourmodel?
TheSunwouldbesmallerthanasinglegrainofsand.Theplanetswouldallbetoo
smalltoseewithoutamagnifyingglass!
Canyouseeapatterntothespacingoftheplanetsinyourmodel?
Yes–aplanetislocatedroughly1.5to2timesthedistancefromtheSunasthenext
closestplanet.Thisonlyholdstrueifwetreattheasteroidbeltlikeaplanet.
Whydidn’taplanetformatthedistanceoftheasteroidbelt?
There are two reasons why no planet formed at the distance of the asteroid belt.
First,eventhoughtherearemanyasteroids,mostareverysmall.Alloftheasteroids
addedtogetherhaveonly0.4%themassoftheEarth(or4%themassoftheMoon)!
Second, both Jupiter and Mars exert gravitational tugs on the asteroid belt. These
constanttugspreventthesmallbodiesfromcomingcloseenoughtobindtogether.
AsteroidsexistallovertheSolarSystem!
Whyisn’tPlutoaplanet?
In 2006 the International Astronomical Union redefined the criteria for a body
orbitingourSuntobeconsideredaplanet.Thesecriteriaare:(i)theobjectmustbe
in orbit around the Sun (it cannot just be passing through!); (ii) the object be
sufficiently massive to have formed a round shape; and (iii) the object must have
beenabletoclearitsorbitoflargedebris.Plutosatisfiestwoofthethreecriteria.It
bothorbitstheSunandhasaroundshape,butithasnotcleareditsorbitoflarge
debris! Pluto’s largest moon, Charon, is 10% the mass of Pluto, and several other
large objects have been discovered around Pluto. Pluto is now considered a dwarf
planet.ItisimportanttorememberthatwhilePluto’sclassificationhaschanged,itis
still there and nothing about it has changed! It is very much like changing which
groupyouworkwithinclass–nothingaboutyouchangesifyouareintheGreenor
Redgroup.
ExtensionsandRelatedActivities
•
DSBKLessons:
PocketSolarSystem–Grade3rd+
•
o ScalemodeloftheSolarSystem
o EdiblemodeloftheSolarSystem
Wiggletimeactivity:PayloadRaces,SpacecraftSprints
Resources
•
•
OnlinescalemodeloftheSolarSystemwherethelengthofthepagerepresentsscale
distancesbetweenplanets
www.scalesolarsystem.66ghz.com
AsimulationofourSolarSystemallowingforviewofallorbitsandhowtherestofthe
SolarSystemmovesrelativetooneplanet
www.gunn.co.nz/astrotour/?data=tours/retrograde.xml
Glossary
•
•
•
•
•
•
AstronomicalUnit–ThedistancebetweentheEarthandSun,approximately1.5million
miles.
DwarfPlanet–AnobjectorbitingtheSunthatislargerthananasteroidbutdoesnot
qualifyasaplanet.
GasGiant–MassiveplanetsintheouterpartoftheSolarSystemcomposedprimarilyof
gas.
LightYear–Thedistancethatlightcantravelinoneyear.
Solar System – The collection of bodies orbiting our Sun. The order of the major solar
systembodiesis:
Mercury–The1stplanetfromtheSun
Venus–The2ndplanetfromtheSun
Earth – The 3rd planet from the Sun, our home and the most massive terrestrial
planet
Mars–The4thplanetfromtheSun
AsteroidBelt–TheregionbetweenMarsandJupiterwithmanyasteroids
Jupiter–The5thplanetfromtheSunandthefirstofthefourgasgiantplanets
Saturn–The6thplanetfromtheSun,knownforitsdistinctrings
Uranus–The7thplanetfromtheSun
Neptune–The8thandfurthestplanetfromtheSun
Pluto–Themostwell-knowndwarfplanet
TerrestrialPlanet–Asmall,rockyplanetorbitingintheinnerSolarSystem