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Objective
To determine the factors affecting
the physical features of the moon and that the craters on
the Moon are impact craters.
To learn more about the terms associated with impact craters.
To understand that impact craters are also found on Earth.
Activity
The circular features so obvious on the Moon's surface
are called impact craters. These were formed when meteorites
smashed into the surface. Have students use the Introduction
to Craters page to find out some basic information about
craters.
Discuss the surface of the moon with students. Talk about
the different features you might find on the moon like hills,
craters, valleys and mountains.Bring out the fact that since
the moon doesn't have any air or water, there is nothing
to cause any erosion on the moon. When the students have
had a chance to discuss the different geographical formations
talk more about the craters. Have the children brainstorm
ideas about how craters were formed. Someone will probably
mention the meteorites crashing into the moon made the craters.
Have the students hypothesize about how different sizes,
different speeds and different dropping heights of meteorites
would affect the size of the crater. Offer a demonstration
of the experiment they will be doing.
Collect items such as marbles, ball bearings, golf balls,
wooden craft balls, etc. These will be used as impactors
and dropped from different heights onto a prepared "lunar
surface." (The lunar surface for this activity will
be flour, topped with a thin dusting of a colored material
such as dry tempra paint.) Students can study the relationship
of the mass (size of impactor) dropped from the same height
to the size of the crater created. Dropping impactors from
different heights will allow students to study the relationship
of velocity of the impactor to the crater size.
Agree on methods to use to resurface the "lunar surface"
when needed. Shaking or tilting pan back and forth produces
a smooth surface. Be sure they know to reapply a fresh dusting
of dry, colored tempera (or other similar material) on top
after resurfacing.
The higher the drop height, the greater the velocity of
the objects so a larger crater should be made and the ejecta
will spread out farther. Have class compare and contrast
their hypotheses on what things affect the appearance of
craters and ejecta. (The factors affecting the appearance
of impact craters and ejecta are the size and velocity of
the impactor and the geology of the target surface.)
Materials Needed
• small round objects to drop
• all purpose flour
• dry tempera paint or powdered drink mixes or glitter
(color is for contrast to flour base and is sifted on top
of "lunar surface")
• plastic or aluminum pans at least 10" x12"
and several inches deep. Larger pans work better and permit
more drops before having to redo the surface.
• Sifter - used to place colored tempra on top which
helps give more striking results to the impacts.
• newspaper or plastic trashbags to place under pans
to catch spills
• meter stick to use for measuing drop height
• balance or scale to weight each impactor which will
be dropped
• copies of student crater
activity sheet
• copies of crater
vocabulary
• Optional - Moon vocabulary
Extension Activities
• Have students explore what happens if they change
the angle of impact?
(If the angle is changed, then the rays
will be concentrated and longer in the direction of the
impact.)
• Some people believe the extinction of the dinosaurs
was caused by a global climate change due to a meterorite
impact on Earth. Have students research the work that has
been done at Chicxulub on the Yucatan coast of Mexico.
(Chicxulub is considered by most scientists as the source
crater of the catastrophe that may have led to the extinction
of the dinosuars at the end of the Cretaceous period. The
Chicxulub crater is nearly a kilometer below the surface
and was identified from magnetic and gravity data.)
• Have students research to find where craters found
on the Earth.
(Some famous impact craters include Meteor Crater in Arizona,
U.S.A.; Manicouagan in Quebec, Canada; Sudbury in Ontario,
Canada; Ries Crater in Germany, Chicxulub in Mexico.)
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Making Craters
