Counting the Stars
This activity was developed be Elizabeth Frank for Project SPICA, August
1991. In it, students practice a technique in their classroom which can
be used on the real night sky to estimate how many stars are visible to
the naked eye.
In this activity, students will....
- predict how many stars are visible in the night sky
- estimate the number of stars in the sky by averaging the number of
stars in a small portion of the sky and extrapolating from their data
- check their predictions
- typing paper (28cm by 22cm)
- three large sheets of opaque butcher paper
- sticky dots or push pins
- Make three sky charts as follows: if your classroom has windows, poke
10-25 holes randomly on a piece of butcher paper. On the second piece,
poke 20-30 holes, and make 30-50 holes on the third piece. It is not necessary
to know exactly how many holes you punch. Hang the butcher paper in front
of the windows. The light shining through the holes will simulate stars.
- If your classroom lacks windows, randomly scatter sticky dots on three
pieces of butcher paper as above. These will represent stars. Hang the
butcher paper on the classroom wall.
- Have each student roll a sheet of typing paper into a tube 28 cm long
and 4 cm in diameter. Fasten with tape. If the tube's diameter is not exactly
4 cm, measure and record the exact diameter.
- Have students stand about 5 meters from the butcher paper, and sight
through the paper tube toward one of the charts. Count and record the number
of stars seen. Repeat for each chart.
- Add together the number of stars from each count and divide by three
for the average (As).
- Calculate the number of stars using the following formula:
- Take the tube home and repeat steps 3-6 looking at the real night sky.
Calculate the number of stars visible.
(Note: the actual number is around 6000, but remember that about 50%
are hidden below the horizon at any given time)
This activity has been copied, with permission, from the
Nebraska Earth Science Education Network server to ours, to allow
access from our web site.
We encourage you to explore the original site.
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