About This Lesson
This lesson has been
designed as a comfortable
introduction to describing
meteorites. It helps students
become better observers by
making a connection between
the familiar (candy bars) and
the unfamiliar (meteorites).
Edible "rocks" are used in a
scientific context, showing
students the importance of
observation, teamwork and
communication skills. In
everyday terms, students draw
and describe the food.
Students will pair their observations
with short descriptions
that are in geologic "Field
Note" style. As the teacher
and class review, appropriate
geologic terminology may be
substituted by the teacher and
subsequently embraced by
even very young students.
The last part of this activity
allows the student to describe
rock specimens before they
move to meteorite samples in
the Meteorite Sample Disk.
Note: Objectives and a
formal vocabulary
introduction should not be
discussed until the end of
the activity.
Objectives
Students will:
- observe and describe physical characteristics of an edible
sample in preparation for describing rock or meteorite
samples.
- work cooperatively in a team setting.
- use communication skills, both oral and written.
Materials
- prepared edible samples (see below)
- small plastic bags for samples
- knife
- "Field Note" Sample Descriptions of candy bars, enlarged and cut
into numbered segments (see below).
Note: If included recipes are not used, then the descriptions may
need to be revised by the classroom teacher to more accurately
describe the actual samples.
- Student Procedure (see below, one sheet per team of two)
- colored pencils for each team
- pen or pencil
Procedure
Advanced Preparation
1. Prepare samples. Simple recipes are included for some
samples. The first six listed on the answer key are especially
important since they closely represent meteorite characteristics
that will be taught in other lessons. The other samples on the
list are good for meeting the objectives of this activity and
offer more variety. Use as many as needed, add a few extras
to complicate the exercise.
2. Cut the samples so that a flat interior surface is exposed.
Reserve part or most of each sample - to be eaten by the students as a reward.
3. Place each sample for student teams in a small plastic bag. Each team of two students will
have one bag containing one sample.
4. Copy Student Procedure sheets, one for each team of two.
5. Cut enlarged "Field Note" Sample Descriptions into numbered segments. Descriptions are
written the way a scientist might take notes in a field record book.
6. Arrange one set of prepared "Field Note" descriptions on a table(s) so that students may easily
read and reach each of them (numbered sequence is not important).
7. Have answer key available for teacher.
8. Have a variety of rock samples available (students may bring their own samples).
Classroom Procedure
1. Distribute sample and procedure sheet to each team. Allow student teams to choose sample if
possible.
Note: Content vocabulary should not be expected initially. The processes of observing and recording
should be kept simple.
2. Explain that each team is responsible for describing and sketching its sample. Encourage
students to describe their observations using familiar vocabulary; however, use no food
terms. Example: The outer layer is a thin coat of light brown material containing cream or tan
colored round chunks (i.e., chocolate candy bar coating that contains peanuts).
Student descriptions need not be exactly like the provided descriptions. In fact their
descriptions may be far more detailed than the short descriptions provided, which are in
geologic "Field Note" form.
3. Emphasize that working together is important.
4. When sketch and description of sample are
complete, students take them, along with their
sample, and pair them with the prepared
written descriptions. Emphasize that their
observations will not be exactly like the "Field
Notes." They will likely try several matches
before they have the accurate paring.
Throughout this step, the teacher will verify
correct pairs. Expect questions like, "Is
number one peanut brittle?". When they have
found the "Field Note" that describes their
sample, students should place their sketch,
description, and sample next to the correct
"Field Note" description. Reward the
students by allowing them to eat the reserved part of the candy or other treat. If students have
difficulty finding the description of their candy bar then the teacher should encourage them to
interact with other groups for help. This step of the lesson will likely become a slightly noisy,
cooperative process. As students find a match between "Field Note" descriptions and candy bars,
some definitions may be supplied if necessary, i.e. "Platy means flaky flat material."
Time: Classroom Steps 1 thru 4 take 25-30 minutes total.
5. When all students have successfully matched their samples, each team may describe its sample
to the class. The class should have access to the sample and the prepared written description
during this sharing. Sketches may be displayed.
6. Conduct a discussion that includes the following points which emphasize basic skills needed to
be good scientists:
- The students made detailed observations of a sample.
- The task was accomplished by using teamwork.
- Although the student’s descriptions differed from those provided and each team had a
different style, the skills and processes used to observe and record the data were the
same for each group.
- The students communicated their observations and then shared the findings verbally
and in writing.
7. During the discussion, the teacher may expand and help define the meteorite and geologic
vocabulary in context and encourage students to apply it to their own samples as they progress
to the next step. Pay particular attention to vocabulary for the first six samples that use some
words especially pertinent to meteorites.
8. Have students test their observation skills again by sketching and describing real rocks.
Vocabulary
texture, density, matrix, breccia, phases, fusion crust, chondrules, inclusions, vesicles, bleb, friable,
platy, porous, unfractured, unconsolidated, regolith
Extension
Using Meteorite Sample Disk or photographs of meteorites in disk, students repeat the same
procedure of observing and recording (or see Lesson 9-Meteorite Sleuths!).
Teacher Key
1. Peanut Brittle (chondrites)
2. Rocky Road (chondrites)
3. Chocolate (iron without fusion crust)
4. 3 Musketeers™ (achondrite with fusion crust)
5. Rice Cereal Treats (meteorite regolith breccia)
6. Chocolate brownie (carbonaceous chondrites)
7. Snickers™
8. Milky Way™
9. "Bar None"™
10. Hershey Bar™
11. Twix™
12. Butterfinger™
13. Skor™
14. Rolo™
15. Kit Kat™
16. Symphony™
17. M & M™
18. Nestle Crunch™
19. Whatchamacallit™
20. Mounds™
21. P.B. Max™
22. Mr. Goodbar™
23. Hershey with Almonds™
Recipes for samples not easily available commercially.
Note: Recipes are for a larger quantity than required for the lesson.
Rocky Road (#2 Edible Rock)
170 g (6 oz.) semi-sweet chocolate pieces (melted)
120 g (2 cups) mini-marshmallows
- butter loaf pan or folded foil
- pour about half of melted chocolate into pan
- pour marshmallows into pan and mix so
they are coated with chocolate
- pour remaining chocolate over the
marshmallows and spread flat
- refrigerate until cold
- cut a cube so vertical surface is exposed
Solid Chocolate (#3 Edible Rock)
use any thick chunk of solid chocolate
Chocolate Brownies (#6 Edible Rock)
- use any recipe for dark chocolate brownies or
a box mix
- add large chunks of semi-sweet baking
chocolate or solid chocolate candy (add
enough so that the solid candy will be
exposed on a cut surface)
- bake and cool completely
- cut, exposing some brownie and some solid
chocolate; this surface will be described
- to form the breccia texture, cut the cube in
several places, then reassemble the cube
in a jumbled manor, incorporating one or two
jelly beans and or other edible chunks
- allow the sample to harden so that a good
surface may be cut
- cut the sample so that chunks and various
chocolate lines are exposed
- students will describe the cut surface
Regolith Breccia Simulant ( # 5 Edible Rock)
(Marshmallow cereal treats)
240 g (1/2 cup) butter or margarine (melted)
300 g (10-11 oz.) mini-marshmallows
200 g (8 cups) crispy rice cereal
170 g (6 oz.) chocolate semi-sweet pieces (melted)
1 or 2 jelly beans, chocolate chunks,
or other large edible lumps
- butter a deep rectangular baking pan
- melt butter in microwave or in large pan on
the stove
- add marshmallows and melt
(2 min. in microwave)
- stir until smooth
- pour over cereal and stir to coat all cereal,
- press half of mixture into deep buttered pan
- spread cereal layer with melted chocolate
- press remaining mixture on top of the
chocolate
- allow cookie to cool enough to cut but not
until completely hardened (should still be
partly moldable)
- cut one cube about 5 cm square, then cut again
once or twice
- embed one or two jelly beans in part of the cut
cube
- mold cut pieces together again to form a
"breccia"
- allow to harden
- recut to expose interior and jelly bean
Student Procedure
Materials - Per Two Students
- sample "rock"
- this procedure sheet
- pen or pencil
- map pencils
Procedure
1. With your partner, choose one sample to observe.
2. Carefully observe the sample. You may remove the sample from the bag,
but handle it carefully and do not taste.
3. Make a large, detailed sketch of the sample. The sketch should show the
interior cut surface that is flat and any important details of the exterior. You
may use the back of this paper for your sketch.
4. Write 2-3 sentences describing the physical characteristics of the cut surface
of the sample. Do not use any food terms. For example, do not use the
word chocolate. Make your description as clear and complete as you possibly
can.
5. When you have completed Step 4 take your description, sketch and sample
to the table where the "Field Note" descriptions of the food samples are
located. Find the description that fits your sample. Check with your teacher
to see if you identified the correct match. You will likely try several of the
descriptions before you find the one that describes your sample. You may
get help from others. Try checking with the teacher or a dictionary for
unfamiliar words.
6. Place your description, sketch, and sample beside the "Field Note"
description for your sample.
7. Your effort will be rewarded with another part of the sample to eat.
Field Note. Sample Descriptions
These food descriptions are in geologic "Field Note" style. Therefore, they may be short and
sometimes cryptic. Use of geologic terms will encourage students to stretch their minds.
1. Sample is a thin layer. There is a golden matrix surrounding tan
rounded or broken inclusions. The inclusions have a
reddish brown rim or crust.
2. Sample consists mainly of white, soft rounded to angular blebs
completely surrounded by a uniform dark brown matrix.
3. Sample is a solid dark brown dense mass with no obvious
fusion crust.
4. Sample has a homogeneous light brown interior with a few small
vesicles. The exterior looks like a fairly regular, dark brown
fusion crust with some patterning.
5. Sample appears to have been distorted. The dominant phase is
made of rounded light tan fragments containing many void spaces.
A dark brown thin layer fills spaces between some rounded
fragments. There are some large foreign inclusions.
6. Sample is totally dark brown with two phases. The dominant phase
is shiny and crumbly. The other phase is dense and slightly lighter
in color. A light fusion crust appears on only one side.
7. Outside: Thin medium-brown layer with ripple-marks
on the bottom
Inside: Bottom - (~1/3) flat dense buff layer
Top - (~2/3) pebbles consolidated in a fine grained
tan matrix
8. Outside: Thin medium brown layer with wavy ripple marks
on the bottom
Inside: Bottom - dense dark buff layer
Top - shiny, smooth, medium tan layer
9. Outside: Medium brown layer, thin on the bottom, the
thicker top contains angular inclusions
Inside: Thin alternating horizontal layers of
smooth dark brown and fragmented dark
brown
10. Dense medium brown sample, flat on the bottom with three
parallel ridges on top.
11. Outside: Thin medium brown layer with wavy ripples on
the bottom
Inside: Bottom - poorly consolidated light tan
porous layer
Top - shiny smooth medium tan layer
12. Outside: Thin medium brown layer
Inside: Poorly consolidated, friable, shiny to dull golden
platy fragments
13. Outside: Medium brown layer, very thin on bottom and
side, thicker on top with large wavy ripples
Inside: Thin dense layer of shiny light-golden unfractured
material
14. Outside: Thin, medium brown, edges higher on outside of
top, sides slanted
Inside: Smooth material that is yellowish brown and
sticky
15. Four segments of layered material.
Outside: Thin, medium brown
Inside: Alternating light and medium
colored material
16. Solid medium brown throughout, single dense layer with a valley
or dip in the top.
17. Sample consists of unconsolidated pebbles with various colors and
regular shape. Each individual pebble has a medium brown interior
with a thin, hard colored shell.
18. Sample has a thin layer of dense brown material, containing very
light inclusions at the bottom. The sample top has a depression in
the middle with a ridge on each side.
19. Sample is a rectangular layer of rounded light pebbles
surrounded by a thin coating of medium brown. Some
yellowish brown sticky material is above the pebbles.
20. Sample interior consists of white, moist-looking fragments.
These are surrounded by a dark brown exterior layer.
21. Irregular sample.
Outside: Bumpy medium brown
Inside: Yellow brown solid material resting on light tan
fragments, some large tan fragments are found near
the top
22. Outside: Dense layer of medium brown with a dip in the top
Inside: Light tan pebbles that have settled to the bottom
23. Dense sample of medium brown material, rounded on the top and
flat on the bottom, with a few light brown pebble
inclusions.