Teacher
Preparation
- Read and become familiar
with the Background section and any additional resources you think
might help you. See "Relevant Resources" at the end of
the section, Background: Impact events are Key to Earth's History.
- Read all the way
through the lesson plan to tailor the ideas to your class and
to be comfortable with the sequence and information.
- Consider running
a classroom lab
that gives students experience at making craters of their own. Guidelines
for such an activity can be found at:
Deep
Impact: Making Impact Craters!
Note:
This is a large Adobe Acrobat PDF file: "craters.pdf"
(8.5 Mb), so you may want to download to your computer (use the
"Save this link as" or "Download link to disk"
option.)
Although impacts of extraterrestrial objects onto the Earth's surface
occur at hypervelocity (high speed) and involve much more kinetic
energy than any impacts in a classroom lab might do, such a lab
can be worthwhile. In this classroom lab, students make craters
themselves and can notice how impacts of different-sized objects
at different angles can produce differently shaped craters.
- Make student copies
of the satellite images on transparencies or paper.
Indicate the abbreviated name of the landform on each student copy
of the image. (See "Materials
and Resources Provided".) If you use the full name, some
students may recognize the landform as an impact crater or other
landform such as a volcano known to them (Mount St. Helens).
- Make student copies
of the worksheets and readings:
Student Worksheet for Step 1: When an
Extraterrestrial Object Hits the Earth
Student Worksheet for Step 2: Known
Effects of Impact Events
Student Worksheet for Step 4: Describing
Satellite Images of Possible Impact Craters
Student Worksheet for Step 6: Questions
You Would Ask on a Field Expedition to a Possible Impact Crater
Please Note: It is recommended that teachers not distribute student
readings before it is indicated to do so in the activity steps below.
If students apply their own existing knowledge to a problem before
doing the reading, the teacher will (1) have a better grasp of what
the students know before they complete the activity; (2) give the
students a chance to struggle with a problem and bring all their
own resources to bear on it.
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Thursday, August 14, 2003