Doomsday Asteroid, The
Ideas from Teachers
One can calculate the minimum energy that an asteroid had when it struck. Simply calculate the work done in excavating the crater. (See the Crater Analysis
printable activity.) To what "height" one chooses to excavate the matter will effect the energy of course. A true calculation of the minimum would involve bringing the excavated material only to the same height as the edge of the crater. One would probably assume a hemispherical crater and some standard density for the material excavated.
Sent in by
David E. Ruppert
Academy of the Holy Cross
In our department we teach an intro astronomy course to both traditional-aged students and adult learners. We use several NOVA programs (and others from Cosmos, the Astronomers, Planet Earth, the Day the Universe Changed) to support our lectures. We have found that students stay more focused if they have a study guide to be completed as they are viewing the program. Consequently, we have written study guides for these NOVA programs:
- "Kidnapped by UFO's?"
- "Death of a Star"
- "Eclipse of the Century"
- "The Doomsday Asteroid"
The students are much more active in learning when they are actively seeking the answers to the questions. We reward their effort by selecting test questions from among the study quide questions. At the end of the program, we review the questions. This always results in a lively discussion of the content of the program.
When this course is taught in our Evening Degree program, the sessions are 8 weeks long. The course carries 6 hrs credit and meets for 3.5 hours, three nights a week. I usually break the class into three distinct sections:
- 60 - 75 minutes lecture
- 70 - 80 minutes video presentation and discussion
- 60 - minutes for a laboratory exercise
This gives the students varied activities with short breaks between. The "Kidnapped by UFO's?" presentation is used the first night as an introductory laboratory exercise to get the students to think about the scientific process of getting to the truth.
The study guide follows:
AST 121: Introduction to Astronomy
Video Study Guide: The Doomsday Asteroid
This program concerns an important question—are you likely to be hit in the head by a asteroid, comet, or meteoroid? The video attempts to answer several provocative questions including: What causes craters? Are there any craters on the earth? Do meteoroids ever hit nearby people? Where do the objects that cause craters come from? Where did the asteroid that may have caused the mass extinction at the end of the Cretaceous period 65 million years ago? How can man prevent asteroids and comets from hitting the earth? What happened on Jupiter in July of 1994?
The presentation features interviews with astronomers including Gene Shoemaker, Carolyn Shoemaker, and David Levy, codiscoverers of the infamous Comet Shoemaker-Levy 9. Also, appearing are planetary scientists and astronomers David Raup, Steve Ostro, Duncan Steele, Clark Chapman, and geologist Glenn Penfield, the discoverer of the 65 million year old Chixalub impact site. Animation and location shots from around the world are blended with telescopic data on comets and asteroids.
What happened in the Tunguska River Valley in Siberia in 1908? How does this explanation compare with the explanation given by Professor Sagan in Cosmos: Heaven and Hell that you viewed earlier in the course?
Do meteoroids ever hit close to people? Give one example.
What is the origin of comets, asteroids, and meteoroids?
Where in the solar system are the rocky asteroids found?
Where are the two regions in the solar system in which the icy comets are found?
Why is the Nullarbor Plain of Western Australia a good place to find meteorites? What is another good place?
About how fast is a meteoroid traveling when it his the earth's atmosphere?
How much meteroidal material falls to the earth each year?
What does the term uniformitarianism mean?
Where did the asteroid suspected of causing the demise of the dinosaurs hit? How did Glen Penfield discover this important impact site?
What is the frequency of major asteroid strikes?
How many asteroids cross the earth's orbit?
What organization has recorded the most meteor explosions in the earth's atmosphere?
What might be a practical use of the SDI technology (Ron's Ray Gun) now that the Cold War is over?
What did David Levy, Carolyn Shoemaker, and Gene Shoemaker discover on 3-23-93? How was this discovery made? (Note: Gene Shoemaker was tragically killed in an auto accident in Australia in 1997.)
What effect did these objects have when they struck Jupiter?
How much energy was released when nucleus G of Comet Shoemaker-Levy 9 hit Jupiter?
What effect would occur if these objects had hit the earth?
How well prepared is mankind to deal with the treat of an asteroid impact?
Is this risk real or is it just another piece of new age nonsense?
Editor's note: You can contact B. Gray Bowman directly for study guides to accompany "Kidnapped by UFO's?," "The Death of a Star," and "Eclipse of the Century."
Sent in by
B. Gray Bowman
High Point University
High Point, NC