NotesFAQContact Us
Search Tips
Back to results
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ989542
Record Type: Journal
Publication Date: 2012-Mar
Pages: 7
Abstractor: ERIC
ISSN: ISSN-0887-2376
Explaining Four Earth Science Enigmas with a New Hypothesis
McGarry, Mary Ann; Straffon, Dan; Patterson, Chuck
Science Scope, v35 n7 p35-41 Mar 2012
The evolution of science is seldom about solitary individuals busy at work in labs making discoveries. This is especially true of the Earth sciences, where time-intensive fieldwork is usually required. Single scientists are rarely capable of amassing the requisite data sets to form grand, unifying theories. This is the case with the new airburst theory put forth by a large team of interdisciplinary scientists, including geologists, chemists, and anthropologists, who are trying to help explain several mysteries involving climate change and extinctions. The airburst theory, alternately known as the Younger Dryas impact or Clovis comet hypothesis, potentially explains four events: (1) Could a meteor entering the Earth's atmosphere around 12,900 years ago be responsible for the mass extinction of the megafauna of North America--the large sloths, mastodons, woolly mammoths, and saber-toothed cats found in the fossil record?; (2) Could this meteor also have caused the end of the Clovis culture, the first well-established Paleo-Indians in North America associated with a particular projectile point?; (3) Could this meteor have put enough debris into the atmosphere to bring about what's called the "big freeze," or the Younger Dryas, a geologically brief cold climate that occurred approximately 12,800 to 11,500 years ago?; and (4) Could this meteor have hit the massive ice sheet over North America, sending smaller particles ricocheting off the ice to form the elliptical depressions collectively called the Carolina Bays? The debate really got started when a diverse team of scientists published an article postulating the connection among the four previously unexplained historical events described above (Firestone et al. 2007). The article was cited in a case study in a nontechnical textbook widely used in university courses (Keller and Blodgett 2008). The authors decided to turn the case study into a lesson plan for middle school students to teach Earth science concepts, along with a bit of archaeology, astronomy, and something about the nature of scientific discovery. The lesson plan is about posing the four questions above and having students find and evaluate evidence to explain each event and then engage in critical thinking to see how the events might all be connected through an emerging theory. An early version of the lesson plan became a piece of action research and was piloted in three eighth-grade middle school classrooms. The lesson is also linked with the newest science education standards. (Contains 2 figures, 18 resources and 12 online resources.)
National Science Teachers Association. 1840 Wilson Boulevard, Arlington, VA 22201-3000. Tel: 800-722-6782; Fax: 703-243-3924; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Grade 8; Middle Schools
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A