This case study deals with the newly derived theory that David French proposes to be effective in diverting asteroids away from planet Earth. David French is a doctoral candidate in aerospace engineering at North Caroline State University. His theory deals with attaching a long tether and ballast to the asteroid or incoming object that would be incoming toward Earth (Science Daily). Tether is a chain or ropelike material that will hold down the ballast, which is added weight. This extra weight distribution according to French of an oncoming object, such as asteroid, will change its center of mass, which ultimately will cause the object into changing its orbit. Once the asteroid has been altered into changing its orbit, it will pass by Earth, without impacting it (Science Daily).
NASA’s Near Earth Object Program located more than 1,000 asteroids that are considered potentially hazardous, and more and more are identified as time progresses. "While none of these objects is currently projected to hit Earth in the near future, slight changes in the orbits of these bodies, which could be caused by the gravitational pull of other objects, push from the solar wind, or some other effect could cause an intersection," as explained by French ( Science Daily).
The effects of Earth getting hit by objects from space have had bad effects. Sixty Five million years ago, in the southern Gulf of Mexico, a very large asteroid is thought to have hit the Earth and wiped out the dinosaurs. In 1907, a small airburst of a comet flattened a forest over an area equal in size to New York City, in Siberia (Kallman, 1998). French’s theory deals with using a tether somewhere between 1,000 kilometers, which is equivalent to roughly the distance from the Capital of North Carolina to Miami, to 100,000 kilometers, which is equivalent to wrapping around the Earth two and a half times.
Multiple theories will be proposed, and students are to determine, and come up with a debate on why they should or should not choose which theory will work. In a class of 12 students, the class would be split into four groups with three people in each group. Each group will be assigned a certain theory, and they have to discuss on which theory would work, and come with a power point presentation, or experiment that what will express their research made on the theory.
There are many theories out there, along with French’s theory, and some of the more believable ones all deal with altering an asteroids orbit, or trajectory path. One theory is to place highly reflective mesh or painting the asteroid in order to alter its orbit by sun’s light changing the asteroid’s spin, moving it into a different orbit. Another theory is to send a probe to orbit the asteroid, and the probe itself will orbit the asteroid in its own off centered orbit, which will eventually knock the asteroid off course(NASA). One other theory is nuclear weapons, which poses a lot of problems politically and technically. The threat involved with using nuclear weapon is very high based on the outcomes becoming more disastrous, because the asteroid could break into multiple asteroids (Science Daily).
Students will have to apply all their knowledge on the physics behind an object moving, and research on all the theories before they support or reject their theory. Within their experiments the students can see how much weight can affect an objects movement, and they can simulate how orbits are affected by various altercations. Groups experiments can greatly affect students perspectives, cause they are exposed to various opinions of peers and they all have to combine their theories together to find answers.
North Carolina State University (2009, April 20). How To Deflect Asteroids And Save Earth. ScienceDaily. Retrieved April 27, 2009, from http://www.sciencedaily.com¬ /releases/2009/04/090416125212.htm
Kallman, Tim (1998). Did an asteroid ever hit Earth?. Retrieved April 20, 2009, from NASA's Imagine the Universe Web site: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980419c.html
NASA, (2009). General Information on Asteroids. Retrieved April 21, 2009, from National Aeronautics and Space Administration Web site: http://nssdc.gsfc.nasa.gov/planetary/planets/asteroidpage.html
