Absorption and Radiation
The temperature range of outer space and on planetary bodies is affected
by a wide range of factors. In outer space, the temperature on a surface
depends upon whether that surface is in sunlight and if so, the angle
of that surface to the Suns rays. On a planetary body, the temperature
also varies with the ambient atmospheric temperature, winds, and nearby
surface materials. For example, on Earth temperatures can vary dramatically
on a summer day between asphalt parking lots and grassy borders.
When designing spacesuits, it is important to account for the temperature
range of the environment for which the suit is intended. Heating and cooling
systems inside a suit can moderate temperatures, but electric power to
operate these systems limits the length of time the suit can be used before
recharging. One way to reduce the dependency of a spacesuit heating/cooling
system is to use materials for suit construction that have desirable thermal
properties. If, for example, a suit is operated in a very cold environment,
good insulating material will reduce the need for internal suit heating.
This activity investigates the affect surface color has on heat absorption
Materials and Tools Checklist
- Coffee cans with plastic lids
- Flood lamp (optional)
- Various colors of paint
- Foil, construction paper, etc.
- Refrigeration (see step 6)
To investigate the effect different colors, reflective surfaces,
and different materials on radiant heat absorption and heat radiation.
Step 1. Paint the surfaces of several coffee cans in different colors
such as white, black, green, or yellow.
Step 2. Punch a small hole in the plastic resealable lid and insert
a thermometer bulb to approximately the middle of each can.
Step 3. Place the cans in sunlight so that all are equally exposed.
Immediately record the initial temperature of each can. If you are doing
the experiment inside, expose the cans to a flood light. It is important
that each can receives the same amount of heat from the lamp. Measure
and record the temperature of the cans every minute.
Step 4. Remove the cans from the heat source after 10 minutes and
measure and record their temperatures again for the next 10 minutes. Graph
your data. Relate the temperature rise and fall of each can to its surface
Step 5. Change the surface material of the cans by wrapping them
with aluminum foil, gray construction paper, or cloth. Repeat the experiment
to find the best combinations of colors and surfaces for different environments.
Step 6. Repeat the experiment by subjecting the cans to intense
cold. The cans can be placed in a freezer or in a tub with ice water or
a block of dry ice.
In this activity, students explore the insulative properties of
Step 1. Stack different fabrics, paper, and foils, and fold
them into small envelopes. Insert a thermometer and repeat the previous
experiment to determine the heat absorption and reflection properties
of different material combinations.
Conduct chromatography experiments on various ink colors
to see what their component colors are. Black inks often consist
of several colors. The reason for mixing several ink pigments is
to make a darker black (more complete absorption of light). (The
Space Shuttle uses black heat shield tiles on the bottom of the
orbiter to quickly dissipate the heat produced when reentering Earths
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