Making Craters
Activity:
Students investigate cratering by modeling the event by dropping rocks
into flour.
Science Standards:
Nature of Science, Energy & Matter, and Scientific Models
Objectives:
The student will create a dynamic model of an impact crater.
The student will identify the variables that characterize a crater.
Materials:
a shallow plastic container (like for cat litter)
flour or any inexpensive white powder
dark sand or any inexpensive dark powder
meter stick
several small rocks
Introduction:
The craters found on the Moon range in size from micrometers to hundreds
of miles across. These craters are formed by impacts from comets or asteroids
of varying sizes. A crater is characterized by a crater wall with radial
"rays" extending out like a wagon wheel from the center. Very large craters
have a "central peak" formed as the surface rapidly rebounds from the impact.
Craters on the Moon will last until another impact destroys it because
there is no weathering or plate tectonics on the Moon to erase the crater.
Alternatively, on the Earth, there are 127 known impact craters remaining.
The most well known of these is the Barringer Crater in Meteor Crater,
Arizona. It is almost a mile across, 600 ft. deep, and 40,000 years old.
Many scientists speculate that a large impact some 65 million years ago
initiated an enormous extinction in which 80% of all species in the ocean
and 90% of all species on land became extinct, including the dinosaurs.
Directions:
1. Place a 2 inch layer of flour in a plastic container.
2. Sprinkle a light layer of dark material, dirt, or sand across the
surface.
3. Drop a small rock from 6 ft. into the container.
4. Remove the rock (it typically disintegrates on impact) and identify
the central crater wall, rays, and other changes that have taken place
in the container.