Download scale_moon

Hey Guys –
I went to that workshop yesterday, which was decently informative – more important was that it
gave me a bunch of ideas for what we can teach this quarter. One thing to definitely keep in mind
is how many preconceptions and misconceptions kids are going to have about this stuff (Ross,
I’m guessing you’ve been learning about this, too). Some of this might be a little high end for the
younger kids – let me know what you think:
1 – Sense of Scale Demonstration – Good intro discussion, get kids to understand how big the
sun is relative to the earth and moon, and how far the earth and moon are from the sun. Can also
do how far the nearest star would be (Alpha Centauri).
-
Introduce concept of scale, and why it’s important to keep in mind what the scale of
things are (models are often misleading for practical purposes, etc.)
o Why do we have models?
o What makes a model “look” correct?
o What are some examples of models you can think of?
-
We must question what part of a model is useful/realistic, and what part is not
-
Get a basketball to represent the sun
“If we shrunk the sun down to this size, how big would the earth be?” (have a couple of
objects for kids to guess on)
o earth is about 1/100 diameter of the sun, so it would be about the size of a
ballpoint pen tip
“What about the moon? Is the moon bigger or smaller than the sun? the earth?” (it’s
about a quarter diameter of earth)
How do the earth, sun, and moon move around each other? (can get kids to act this out)
What is an orbit? What is rotation? (don’t use the word “revolution” – gets confusing)
How long does it take for the earth orbit the sun? (365 days) The moon to orbit the earth?
(about 28 days)
How long does it for the earth to rotate once on its axis? (24 hours)
How far is the earth from the sun on this scale? (85 feet)
What about other planets (refer to list below)?
“On this scale, how far is the moon from the earth?” (2 inches or so)
-
Concepts to get across:
- scale of earth, sun, and moon
- scale of distances between them
- normal models are incorrect in portraying these things
Materials needed:
- basketball
- a few small objects to be the planets
- signs for planets
Scale distances for sun = basketball (9.5 inch diameter)
Distances from sun (millions of km)
inches
feet
Mercury
58.00
395.83
Venus
108.00
737.07
Earth
150.00
1023.71
Mars
228.00
1556.03
Jupiter
778.00
5309.63
Miles
32.99 0.00624737
61.42 0.011633033
85.31 0.01615699
129.67 0.024558625
442.47 0.083800922
Saturn
Uranus
Neptune
Pluto
Earth to moon
Sun to Alpha Centauri
Sizes
Sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
1427.00
2871.00
4497.00
5913.00
0.38
3.80E+13
9738.86
19593.75
30690.73
40354.53
2.62
2.59E+14
811.57
1632.81
2557.56
3362.88
0.22
2.16E+13
0.153706833
0.309244792
0.484386565
0.636908552
4.13619E-05
4.09E+09
real diameters (km) inches
cm
scale factor
1,392,000
9.5
24.13 146526.3158
4878 0.033290948 0.084559009
12104 0.082606322 0.209820057
12756 0.087056034 0.221122328
6794 0.046367098 0.117772428
142796 0.974541667 2.475335833
120,660 0.823469828 2.091613362
51,118 0.348865661 0.886118779
49,523 0.337980244 0.85846982
2,300 0.015696839 0.039869971
2 – Phases of the Moon Exercise – gather preconceptions of what the kids think causes the
phases of the moon, try and dispel those notions, empower them to go home and teach to
someone (?) – remember to keep referring back to sense of actual scale while doing this exercise
May want to do this a little more free-form – have the kids explore with the balls and lamp first,
then lead them through the exercise (or lead them through it without saying what they are
doing…)
-
-
Do you know what the phases of the moon are? Does the moon look the same every
night? (different shapes that the moon takes on at night)
What causes the phases? (write these ideas down on the board – probably will say things
like earth’s shadow, clouds, etc.)
Have all kids stand around in a circle around the sun (lamp in center of room), each with
a Styrofoam ball
Convey that each of our heads is the earth, the styrofoam balls are the moon
o From what we know of correct distances and sense of scale, what’s wrong with
this model?
Hold styrofoam ball up to the light so that it blocks the sun – what phase is this? (new
moon)
Turn around (to the left) 180 degrees and hold balls so that head is not blocking the light
– what phase is this? (full moon)
Turn back around to face front
Hold your moon to your left in left hand to face your neighbor – what do you see? (half
moon)
Notice that if you stick your right arm out at a 90 degree angle to your left arm, it will point
toward the sun
Hold at a 45 degree angle from line between you and the sun – what do you see?
(crescent)
Bring back what they’re seeing to previous ideas
o when you hold the moon out to your left, where is the earth’s shadow?
o Are there any clouds to block the view and make the shape that you see?
-
start at front again, how long does the moon take to go around the earth?
When do we see the moon? (at night) Which direction do we face at night? Is the moon
out during the day? Can we see the moon during the day?
What’s an eclipse then?
o May need to use ball models to show this
o Earth, moon, and sun all aligned (moon between earth and sun = solar eclipse,
earth between moon and sun = lunar eclipse)
o Why doesn’t this happen all the time? (moon’s orbit not in same plane as earthsun)
Concepts to get across:
- phases of the moon caused by reflection of light from sun, not by earth’s shadow, as
commonly thought
- ideas of a new moon, full moon, when these happen
- how celestial movement corresponds to our sense of time (months, years)
- difference between eclipse and phases
- Extensions for older kids –
o Point out that the same face of the moon is always pointed toward earth (invite
them to observe the moon at different times during the month, see if we can get
some pictures of the moon in different phases to show this)
Materials needed:
- Styrofoam balls on toothpicks or thin, short dowels (one for each student)
- Bright light to represent sun