How to Draw an Elliptical Orbit: A Step-by-Step Guide

hi everyone today we're going to talk about station three of our lab practical we're going to learn how to draw an

elliptical orbit so let's start with our directions page number one says write the eccentricity code number below on

your answer booklet they gave us the code number I'm going to go to my answer booklet right here and I'm going to

write the code number three one next it says on the ellipse construction page the last page in your answer

booklet so it's saying to go to my last page in my answer booklet so let's do that my last page of my answer booklet

looks like this it says Circle the two dots that correspond to the two dots circled in

the line below this is important because it's telling us to Circle F1 and F1 on this side so I'm going to go to my

answer booklet and circle F1 and F1 the reason this is important is because on the lab practical itself you might be

asked to Circle F2 or F3 depending on which student you are different students will Circle different ones so in this

case I'm circling F once number three says place the ellipse construction page on the foam board let's do that here's

my foam board I'm gonna put the ellipse construction page right here one second

and it then says where am I insert a push pin through the center of each circle dot so that the pins are firmly

in the board so that just means that I have some push pins available to me I'm gonna put one of the pins on F1 that are

circled on this side and the other F1 on this side depending on which ones you Circle you're gonna have to put your

push pins in the different areas next number four says place the loop of string around the pins and place your

pencils inside the loop and construct the ellipse here's my Loop that I'm given I'm going to make sure that the

knotted part of my Loop is on the outside it's not touching any of these pins and I'm just going to Loop it

around my pins next I'm going to take my pencil and I'm going to gently stretch out this Loop and I'm going to draw a

nice circle around my pins you might not get it right the first time but if you keep going around you

might have a good oval and that looks good to me so next I'm going to erase this part

actually and then I have my final oval okay next it says number five remove the pins

and string Loop and return them to The Container here's my container I'm going to take my potion and I'm going to take

my Loop and put it away now I have an ellipse right here number six says the ellipse you

constructed represents the orbit of an asteroid around the Sun we're drawing the orbit of an asteroid going around

the Sun now it says place an S above one of your circled Foci to show the position of the sun your Foci are the

circles that you drew around those dots one of them is going to be the sun it's up to you which one you want the sun to

be but either draw an s on top of F1 on this side or draw an s on top of F1 on this side if you circled F2 then you

would draw your s on top of F2 if you circled F3 then you would draw your s on top of F3 this is showing that in our

real solar system the sun is not always in the center of the orbit it's kind of towards this side and the asteroid

orbits the sun around in an elliptical orbit now that I have an S here number seven says place an x on the constructed

orbit where the asteroid has its greatest orbital velocity we want to represent where the asteroid will be

fastest so the asteroid will be fastest closest to the sun which is s so we're going to draw the X on my Orbit

because the asteroid won't be outside the orbit on my Orbit right next to S where the sun is because of Sun's

gravity the orbit will be fastest right here so we have my S we have my X do not draw

more than one X do not draw more than one s because where there's only one sun in our solar system and one asteroid on

our orbit next number eight says use a metric ruler

measure the distance between the foci of the ellipse you constructed let's do that here's my ruler remember my Foci

are where I put my push pins and play in this case F1 and F2 I'm going to measure it in centimeters

and when I measure it I'm gonna always put my zero where I'm starting at F1 right here and I see that my distance

from F1 here and F1 over here is around 4.5678 4.8 I'm gonna put that on my answer booklet

my distance between Foci is 4.8 notice that it says nearest tenth of a centimeter if you go to your

directions page tenth of a centimeter is just one digit after the decimal point so I should have one digit after my

decimal point next is asking for the length of the major axis number nine says measure the length of the major

axis of the ellipse you constructed and record this distance also to the nearest tenth of a centimeter for a recap the

length of the major axis is from one side of your ellipse all the way to the other side in this case if I go back to

my construction page the my major axis is actually from this side of my ellipse all the way to the other side of my

ellipse that I drew I'm going to measure the distance I'm going to put my zero in the first

part right here in the first dot that I drew and I see that the length of my major axis is around

16.567 16.7 centimeters I'm gonna go back to my answer booklet and I'm gonna run I'm

going to write 16.7 it says nearest tenth I know nearest tenth is one digit after the decimal so I'm just going to

write 16.7 lastly number 10 asks calculate the eccentricity of your ellipse and record

it to the nearest thousand you can find your eccentricity equation on your reference table and this equation will

actually be given to you I'm going to use my calculator I know my I need my distance between foca and the top so I'm

actually going to do this here for you over here so distance between Foci and Foci or foci is on the top that's 4.8

centimeters and length of the major axis is on the bottom that's

6.16.7 centimeters 4.8 divided by 16.7 is 0.287 it asks me to write it to the

nearest thousand nearest thousand means three digits after the decimal so I'm just going to write three digits after

the decimal eccentricity never has units so just write this number no units if you do

have units for this it will be wrong so I'm just going to write 0.287. [Music]

all right so number 11 says now we want to record the planet name in this case it gave us Mars in the space provided in

my answer booklet so I'm going to go to my answer booklet there's a space that says planet name they say Mars so I'm

going to ride Mars you might have different planets depending on what student you are so make sure you're

reading your instructions properly number 12 oh it also says use the solar system

data table on page 15 of your reference table to find the eccentricity of the planet's orbit record the eccentricity

to the nearest thousand in your answers page 15 of my reference table looks like this and since we're talking about Mars

Mars is right here Mars's eccentricity can be found in this column in this case is

0.093 this is already written in the nearest thousands so I'm just going to write down

0.093 remember X and trustee does not have units you do not have to add units if you do you will get points taken up

now it says number 12 in the space provided in your answer booklet write down whether the asteroids orbit is more

elliptical or less elliptical or equal to the orbit of the planet now the orbit of my Planet what we're doing right now

is comparing the eccentricity of orbit of my asteroid to the planet Mars the orbit or the eccentricity of the

asteroid orbit is 0.287 the eccentricity of Mars's orbit is

0.093 the bigger eccentricity will be more elliptical meaning more oval so if it's asking is the asteroids orbit more

less or equal to the planet's orbit I would say Mars's orbit is less elliptical than my asteroids orbit

simply because my number is smaller so I'm just going to write no it's asking is the asteroid's orbit

more or less than my planet's orbit my asteroid's Orbit will be more elliptical because it's a higher number so I'm

actually going to write more whichever is a higher number will be more elliptical or more oval

last but not least it asks me to provide an explanation of how I know it's more elliptical and the only answer I need

you to say is this and I need you to memorize this and this will not be given to you on your lab practical the larger

the eccentricity the more elliptical the orbit that's all you have to say every time so I'm going to go ahead and write

the larger the eccentricity the more elliptical

the orbit and that's it for now I'll see you guys later bye