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by Eric Jackson
Many camps are in rural locations where stars are more readily seen
than from towns and cities. Yet most camps don't include any form of
astronomy in their camp programs because they only see it as a night-time
occupation — and one that requires experts and equipment. Carey
Park Christian Camp in New Zealand found a way to overcome this in a
very innovative way. The camp introduced astronomy during the daytime.
An Understanding of Astronomy
Experience shows that campers come to camp with little or no understanding
of astronomy and often confuse it with astrology. They probably haven't
had any astronomy lessons at school and have commonly-held ideas to explain "what
is happening in the sky." The following are two views or perspectives
of "what happens in the sky" — the apparent movement
of the sun during the day.
- Earthbound view — On Earth,
our perception is that the sun, stars, and all other natural objects
in the sky move around us from east to west. We say that the sun "goes
across the sky."
- Astronaut's view — An astronaut
looking at the Earth from far out in space sees the Earth rotating
from west to east as it orbits the sun. They say that, "it is
the earth that is turning."
This apparent motion of the sky varies depending on where you are on
the Earth — so latitude, or where you live is important. To understand
our place in space, we need to hold both views in our mind together.
In many camps, staff who are apprehensive about offering astronomy sessions
at night never even think of doing it during the day. Before attempting
a night astronomy program, you can establish the principles of astronomy
by using shadows during the day.
Daytime Observations
Daytime observations based on the movement and direction of shadows
are intriguing to explore and offer information that most people didn't
understand or know.
- There are two noons every day — 12 o'clock "standard" time
and noon by the sun, which is called solar noon.
- Solar noon is when the sun is half way in time — between sunrise
and sunset at your location and is therefore called local noon.
- At solar noon, the sun is directly south of your location, and all
shadows point to the true North Pole.
- If a camper stands with his or her back to the sun at solar noon,
the shadow lies along a line from the South Pole to the true North
Pole through your camp. The camper's heels point south and his or her
head's shadow points true north.
- Being the true North Pole raises the issue of magnetic north and
the difference between them. Campers can use their shadows as the basis
for a compass to find their way.
- At solar noon we say that the sun is on the meridian — and
that it is noon. Before then, the sun is before the meridian, or ante
meridian (a.m.). After then the sun is past the meridian, or post meridian
(p.m.) and is afternoon.
- The length of the camper's solar noon shadow is directly related
to the season. Short shadows occur in the summer; long shadows are
seen in winter.
Arising out of these points are four basic observations upon which many
astronomical understandings are built. These observations set the scene
for night-time observations:
- At solar noon local time, the meridian is on the sun. The meridian
is an earthbound concept; the correct observation is the meridian is
on the sun. All shadows point to the nearest pole and are aligned true
north/south.
- The sun appears to move in a wide band across the sky between the
longest and shortest days.
- Along this band are found the moon, all the planets, and the constellations
of the Zodiac.
- The height of the sun at solar noon increases from the shortest
to longest day and decreases back to the shortest day, thus creating
the seasons.
The nearest star is the sun, the nearest planet is Earth, and the nearest
moon is our moon. All three can be seen during the day. Understanding
the motions and interaction of these three planets helps explain what
is happening daily, nightly, seasonally, and yearly.
Implementing the Program
With this introductory information and observations, an astronomy program
for campers can be implemented at camp and explored further at home or
school. Many schools use Carey Park's astronomy program to meet their
science curriculum standards. The original daytime astronomy activities
have now developed into a worldwide camp and school astronomy program.
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Resources
The Astronomical Society of the Pacific’s The Universe at
Your Fingertips |
| Activities |
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B-6 “Making Pictures of Motion” (using
a traditional stick), |
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B-7 “Making a sun Clock” (using a sundial), and
B-8 “Plotting the Apparent Motion of the sun” (using
a clear plastic hemisphere). |
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B-9 “Solar Motion Detector” addresses the yearly
interval. |
| The Ever-Changing Sky: A Guide to the Celestial
Sphere by James Kaler |
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Originally published in the 2004 May/June
issue of Camping Magazine.
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