LESSON PLAN
Name: Allyson
Berglund
Title of lesson: Cratering Process
Date of lesson:
Length of lesson:
120 minutes
Description of the class:
Name
of course: Science
Grade
level: 8
Honors
or regular: Regular
Source of the lesson:
http://www.spacegrant.hawaii.edu/class_acts/Craters.html
Hawai'i
Space Grant College, Hawai'i Institute of Geophysics and Planetology,
TEKS addressed:
(b) Knowledge
and skills.
(1) Scientific
processes. The student conducts field and laboratory investigations using safe,
environmentally appropriate, and ethical practices. The student is expected to:
(A) demonstrate
safe practices during field and laboratory investigations; and
(B) make wise
choices in the use and conservation of resources and the disposal or recycling
of materials.
(2) Scientific
processes. The student uses scientific inquiry methods during field and
laboratory investigations. The student is expected to:
(A) plan and
implement investigative procedures including asking questions, formulating
testable hypotheses, and selecting and using equipment and technology;
(B) collect
data by observing and measuring;
(C) organize,
analyze, evaluate, make inferences, and predict trends from direct and indirect
evidence;
(D) communicate
valid conclusions
(E) construct
graphs, tables, maps, and charts using tools including computers to organize, examine, and evaluate data.
(3) Scientific
processes. The student uses critical thinking and scientific problem solving to
make informed decisions. The student is expected to:
(C) represent
the natural world using models and identify their limitations;
(4) Scientific
processes. The student knows how to use a variety of tools and methods to
conduct science inquiry. The student is expected to:
(A) collect,
record, and analyze information using tools including beakers, petri dishes,
meter sticks, graduated cylinders, weather instruments, hot plates, dissecting
equipment, test tubes, safety goggles, spring scales, balances, microscopes,
telescopes, thermometers, calculators, field equipment, computers, computer
probes, water test kits, and timing devices; and
(B) extrapolate
from collected information to make predictions.
(5) Scientific
processes. The student knows that relationships exist between science and
technology. The student is expected to:
(A) identify a
design problem and propose a solution;
(B) design and
test a model to solve the problem; and
(C) evaluate
the model and make recommendations for improving the model.
I.
I. Overview
The object of this lesson
is to get students thinking about what influences crater formation. The students should form hypotheses, perform
experiments, and draw conclusions. This
lesson should tie in math skills, such as mass, density, height, velocity, and
force.
II. Performance or learner outcomes
Students
will be able to:
Define key words: impact, impactor, and ejecta
Determine the factors affecting the
appearance of impact craters and ejecta.
III. Resources, materials and supplies needed
For
each group of students:
1 pan:
Pans
should be plastic, aluminum, or cardboard. Do not use glass. They should be at least 7.5 cm deep. Basic
10"x12" aluminum pans or plastic tubs
work fine, but the larger the better to avoid misses. Also, a larger pan may allow students to drop more marbles
before having to resurface and smooth
the target materials.
"lunar" surface material
all
purpose flour
Reusable in this activity and keeps
well in a covered container.
baking soda
It can be recycled for use in the
lava layering activity or for many other
science activities. Reusable in this activity, even if colored, by adding a clean layer of new white
baking soda on top. Keeps indefinitely
in a covered container. Baking soda mixed (1:1) with table salt also works.
corn meal
Reusable in this activity but
probably not recyclable. Keeps only in freezer
in airtight container.
sand and corn starch
Mixed (1:1), sand must be very dry. Keeps only in
freezer in airtight container.
tempera paint, dry
sieve or sifter
balance
3 impactors (marbles or other spheres)
meter stick
ruler, plastic with middle depression
protractor
For
teacher:
slingshot
IV. Supplementary materials, handouts.
For
each student:
“Cratering Process” Activity Sheet
“Results” Activity Sheet
"Data Chart"
graph
paper
Five-E Organization
Teacher
Does Probing Questions Student
Does
|
Engage: Learning Experience(s) Begin by looking at
craters in photographs of the Moon and asking students to recall how craters
formed. |
Critical
questions that will establish prior knowledge and create a need to know After looking at photographs
of the Moon, how do you think the craters were formed? What do you think are
factors that affect the appearance of craters and ejecta? |
Expected
Student Responses/Misconceptions |
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Explore: Learning Experience(s) During this activity, the
flour, baking soda, or dry paint may fall onto the floor and the baking soda
may even be disbursed into the air. Spread newspapers under the pan(s) to
catch spills or consider doing the activity outside. Under supervision,
students have successfully dropped marbles from second-story balconies.
Resurface the pan before a high drop. Have the students agree
beforehand on the method they will use to "smooth" and resurface
the material in the pan between impacts. The material need not be packed
down. Shaking or tilting the pan back and forth produces a smooth surface.
Then be sure to reapply a fresh dusting of dry tempera paint or other
material. Remind students that better experimental control is achieved with
consistent handling of the materials. For instance, cratering results may
vary if the material is packed down for some trials and not for others. |
Critical
questions that will allow you to decide whether students understand or are
able to carry out the assigned task (formative) Preparing
a "lunar" test surface 1. Fill a pan with surface
material to a depth of about 2.5 cm. Smooth the surface, then tap the pan
to make the materials settle evenly. 2. Sprinkle a fine layer
of dry tempera paint evenly and completely over the surface. Use a sieve
or sifter for more uniform layering. 3. What does this
"lunar" surface look like before testing? Have students answer questions on “Cratering
Process” Activity Sheet |
Expected
Student Responses/Misconceptions Dirt,
ground, rock, Earth |
|
Explain: Learning Experience(s) Have the class compare and
contrast their hypotheses on what factors affect the appearance of craters
and ejecta. |
Critical
questions that will allow you to help students clarify their understanding
and introduce information related to concepts to be learned Have
students answer the questions on the “Results” Activity Sheet |
Expected
Student Responses/Misconceptions |
|
Extend / Elaborate: Learning
Experience(s) As a grand finale for your
students, demonstrate a more forceful impact using a slingshot. |
Critical
questions that will allow you to decide whether students can extend
conceptual connections in new situations What happened to the
marble? How did the crater form? |
Expected
Student Responses/Misconceptions Increased
velocity, increased force Crater
is larger, deeper, more ejecta |
|
Evaluate: Lesson Objective(s) Learned (WRAP ≠UP
at end) -> Summarize |
Critical
questions that will allow you to decide whether students understood main
lesson objectives What is the
relationship between height of object being dropped and size of crater? What is the relationship
between velocity and crater size? If the object has more
force (like using a slingshot), how does that effect crater formation? |
Expected Student Responses/Misconceptions The
greater the height, the larger the crater. Causes
deeper, larger hole, more ejecta When
impactor has a high velocity, the crater will be larger, height effects
velocity |
Cratering Process
1. Use the balance to measure the mass of
each impactor. Record the mass on the "Data Chart" for
this impactor.
2. Drop impactor #1 from a height of 30 cm onto
the prepared surface.
3. Measure the diameter and depth of the
resulting crater.
4. Note the presence of
ejecta (rays). Count the rays, measure, and determine the average length of all
the rays.
5. Record measurements and
any other observations you have about the appearance of the crater on the Data
Chart. Make three trials and compute the average values.
6. Repeat steps 2 through 5
for impactor #1, increasing the drop heights to 60 cm, 90 cm, and 2 meters.
Complete the Data Chart for this impactor. Note that the higher the drop
height, the faster the impactor hits the surface.
7. Now repeat steps 1
through 6 for two more impactors. Use a separateData
Chart for each impactor.
8. Graph your results. Graph
#1 is Average crater diameter vs. impactor height or velocity. Graph #2 is
Average ejecta (ray) length vs. impactor height or velocity. Note: on
the graphs, use different symbols (e.g., dot, triangle, plus, etc.) for
different impactors.
Results
1. Is your hypothesis about
what affects the appearance and size of craters supported by test data? Explain
why or why not.
2. What do the data reveal
about the relationship between crater size and
3. What do the data reveal about
the relationship between ejecta (ray) length and velocity of impactor.
4. If the impactor were
dropped from 6 meters, would the crater be larger or smaller? How much larger
or smaller? Explain your answer. (Note: the velocity of the impactor would be
1,084 centimeters per second.)
5. Based on the experimental
data, describe the appearance of an impact crater.
6. The size of a crater made
during an impact depends not only on the mass and velocity of the impactor, but
also on the amount of kinetic energy possessed by the impacting object. Kinetic
energy, energy in mostion, is described as:
where, m = mass and v =
velocity.
During impact, the kinetic energy of an asteroid is transferred to the target
surface, breaking up rock and moving the particles around.
7. How does the kinetic
energy of an impacting object relate to crater diameter?
8. Looking at the results in
your Data Tables, which is the most important factor controlling the kinetic
energy of a projectile, its diameter, its mass, or its velocity?
9. Does this make sense? How
do your results compare to the kinetic energy equation?
10. Try plotting crater
diameter vs. kinetic energy as Graph #3. The product of mass (in grams) and
velocity (in centimeters per second) squared is a new unit called
"erg."
Use this graph paper to
plot Average Crater Diameter vs. Impactor Velocity 
Use this graph paper to
plot Average Ejecta (ray) Length vs. Impactor Velocity
Use this graph paper to
plot Crater Diameter vs. Kinetic Energy
|
Impact
Craters Data Charts |
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drop
height=30 cm (velocity=242 cm/s) |
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trial 1 |
trial 2 |
trial 3 |
total |
average |
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crater diameter |
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crater depth |
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average length of all rays |
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drop
height=60 cm (velocity=343 cm/s) |
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trial 1 |
trial 2 |
trial 3 |
total |
average |
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crater diameter |
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crater depth |
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average length of all rays |
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drop
height=90 cm (velocity=420 cm/s) |
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trial 1 |
trial 2 |
trial 3 |
total |
average |
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crater diameter |
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crater depth |
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average length of all rays |
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drop
height=2 meters (velocity=626 cm/s) |
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trial 1 |
trial 2 |
trial 3 |
total |
average |
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crater diameter |
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crater depth |
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average length of all rays |
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