Build Your Own Refracting ! Level: Grades (6-8) Credit: Activity by NASA “Building a Telescope” and adapted by NSO https://www.nasa.gov/audience/foreducators/topnav/materials/listbytype/Building_a_Telescope.html Procedure from EpicFanasy / Stormthecastle.com - https://www.youtube.com/watch?v=msIAdyljrwI

Students will be able to...

• Construct a simple • Calculate the magnifcation of telescope • Compare and evaluate telescope designs among peers

‰ 2 Cardboard paper towel tubes or other “tube-like” items

‰ Glue or Tape

‰ Corrigated cardboard : Objective Lens: ‰ X-acto knife or Scissors Convex Convex : 2-4” Focal Length: 8-14” Materials ‰ 2 convex lenses (see “lenses” for Diameter: 0.5-2” Diameter: 1-2” lens options)

In a simple refracting telescope, there are two lenses: the objective lens and the eyepiece lens. from a distant object is focused by the objective lens. This forms an image in front of the eyepiece. The eyepiece acts as a magnifer to enlarge the image.

Magnifcation can be calculated using the following formula: Theory M = focal length of the objective / focal length of the eyepiece Procedure 1. (Optional) Decorateyour telescopewithpaints,markers,orconstruction paper 5. 4. 3. 2. Larger Objective Lens

the unalteredsecondtube. overlap shouldbejustenoughsothattheresizedtubecanftsnugglyinto of onetube.Overlaptheedgesslightlyandtapethembacktogether.The Start withyourcardboardpapertoweltubes.Makeacutdownthelength your image. You nowhaveasimpletelescope!Slidethe smallertubeinandouttofocus attached totheinnercardboardtube. ing eachlenstoaseperatetube.Besurethatthesmallereyepieceis glue ortape.Dothesamewithotherlens/cardboardcombo,attach Attach onelens/cardboardcombototheendofpapertoweltubeusing both lenses. ing thelens,aboutsizeofendyoupapertoweltube.Dothisfor Cut thecardboardaroundlenssothatyouformaringhold fts snuggly.Dothisforbothofthelenses. Cut thecircleout.Pushlensintoholeincardboardsothatit Trace acircleonthecorrigatedcardboardslightlysmallerthanyourlens. Smaller EyepieceSmaller Lens “lens/cardboard combo” - - Observations, Data, and Conclusions 1. Observe anobjectthroughyourtelescope. Magnifcation: ______following formula: Calculate thepowerormagnifcation(M)ofyourtelescope.Use 5. 4. 3. 2.

calculated magnifcation?Whyorwhynot? Does theamountofmagnifcationobserved throughyourtelescopematch How istheobservedimageoriented? larger tube? Are youabletofocusyourimagebyslidingthesmallertubeinoroutof Does theobjectlookclearer? Does theobjectlookbiggerthanwhenobservingwithyoureyesonly? Standards Enrichment • • • • Variables tomanipulate: in engineeringtodevelopevenbetterhomemadetelescopes!:) different typesoflenses,buildingmaterials,andoveralldesign.Applyyourskills Once you’refamiliarwiththestepsneededtobuildatelescope,experiment MS-ETS1-2 MS-ETS1-3.4.1

etc. Tubes -Experimentwithdifferenttubediameters,lengths,materials,shape, Lens diameters-Experimentwithlensesofdifferent Lens focallengths-Experimentwithlensesofdifferent etc. Lens type(e.g.doubleconcave,convex,planoconvex –Evaluate competing design solutionsbasedonjointlydevelopedand – Analyze and interpret data to determine similarities and dif and similarities determine to data interpret and Analyze – agreed-upon designcriteria NSO iain r toe f h ato() n d nt eesrl re necessarily not do and author(s) the of those are lication Any opinions, T e National Solar Observatory is sponsored by the National Science Foundation. Science National the by sponsored is Observatory Solar National e ferences infndings. National SolarObservatory www.nso.edu f ndings, and conclusions or recommendations expressed in this pub National Foundation Science f ect the views of the the of views the ect - -