Name: _____________________________________________ Period: _______ Date: ______________
Impact Craters Lab
Goal: To find a relationship between a projectile and the crater it leaves behind.
Background
Many of the features we see gracing the Moon’s surface are ‘impact
craters’ formed when impactors smashed into the lunar surface. The
resulting explosion and excavation of material at the impacted site
creates piles of rock (called ejecta) around the circular hole as well as
bright streaks of target material (called rays) thrown for great
distances.
Two common methods of craters formation in nature are:
1) impact of a projectile on the surface and 2) collapse of the top of a
volcano creating a crater termed caldera.
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.
By recording the number, size and extent of erosion of craters, lunar geologists can determine the ages of
different surface units on the Moon and can piece together the geologic history. This technique works because
older surfaces are exposed to impacting meteorites for a longer period of time than are younger surfaces.
Impact craters are not unique to the Moon. They are found on all the terrestrial planets (Mercury, Venus, Earth
and Mars) and on many moons of the outer planets.
On Earth, impact craters are not as easily recognized because of
weathering and erosion. Famous impact craters on Earth are
Meteor Crater in Arizona, U.S.A.; Manicouagan in Quebec, Canada;
Sudbury in Ontario, Canada; Ries Crater in Germany, and Chicxulub
on the Yucatan coast in Mexico.
Characteristics of Impact Craters
Typical characteristics of an impact crater are:
Floor: bowl shaped or flat, characteristically below surrounding
ground level unless filled in with lava.
Ejecta rays: blanket of material surrounding the crater that was excavated during the impact event. Ejecta
becomes thinner away from the crater. Bright streaks starting from a crater and extending away for great
distances. See Copernicus crater for another example.
Raised rim: rock thrown out of the crater and deposited as a ring-shaped pile of debris at the crater’s edge
during the explosion and excavation of an impact event.
Walls: characteristically steep and may have giant stairs called terraces.
Central uplifts: mountains formed because of the huge increase and rapid decrease in pressure during the
impact event. They occur only in the center of craters that are larger than 40 km diameter.
Name: _____________________________________________ Period: _______ Date: ______________
Materials:
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1 tray of sand
1 15cm Ruler
1 golf ball
1 Baseball
1 tennis ball
1 softball
1 marble
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Safety goggles are required for this lab, sand in eyes can cut/damage your eyes.
Clean up any spills immediately, sand on tile is slick and a tripping hazard
Use all tools the way they are meant to be used
Safety:
Question:
How does the size, density and composition of a projectile affect the size of crater upon impact?
Hypothesis:
_________________________________________________________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
Procedure:
1. Measure the diameter(cm) and mass(g) of each projectile. Calculate the circumference and density of
each object.
Item
Marble
Ping pong Ball
Golf Ball
Tennis Ball
Baseball
2.1cm3
33.51cm3
40.76cm3
146.46cm3
230.08cm3
Diameter in cm
Circumference in
cm
C = 3.14 * Diameter
Mass in grams
Volume
Density
Mass ÷ Volume
2.
3.
4.
5.
Stand on the table, hold the projectile over the tray of sand on the floor. Drop it. Do not throw it.
Carefully remove the projectile and measure and record the Diameter of the crater(cm) left behind.
Use the ruler to smooth over the sand.
Repeat the test 3 times for each object, record all data on your data sheet
Name: _____________________________________________ Period: _______ Date: ______________
Data Sheet: Impact Craters Lab
Projectile and Crater Data:
Crater Diameter (cm)
Projectiles
Drop 1
Marble
Drop 2
Drop 3
Drop 1
Ping Pong Ball
Drop 2
Drop 3
Golf Ball
Drop 1
Drop 2
Drop 3
Drop 1
Baseball
Drop 2
Drop 3
Drop 1
Tennis Ball
Drop 2
Drop 3
Average Crater Diameter (cm)
Name: _____________________________________________ Period: _______ Date: ______________
Plot your Data: Projectile Circumference vs Crater Diameter
Use the graph below to plot your projectile circumference (y axis) versus average crater circumference (x axis)
Name: _____________________________________________ Period: _______ Date: ______________
Plot your Data: Projectile Mass vs Crater Diameter
Use the graph below to plot your projectile density (y axis) versus average crater circumference (x axis)
Name: _____________________________________________ Period: _______ Date: ______________
Conclusion:
1. What conclusions can you make about projectile size and crater size? Refer to the graph you made.
2. What conclusions can you make about projectile mass and crater size? Refer to the graph you made.
3. Was your hypothesis correct or not? Explain.
4. What experiments or tests would you like to run next to learn more?