Teacher resources and professional development across the curriculum
Teacher professional development and classroom resources across the curriculum
Teacher Joe Reilly asks the question, "How did our solar system form?" In 1755, a renowned German philosopher, Immanuel Kant, developed the currently-accepted "Solar Nebula" theory. He described how a solar system can develop from clouds of dust and gas that collapse into a flat spinning disk. Dr. R. Hank Donnelly, from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, describes in more detail how clouds of dust and gas produced in proto-solar nebulae coalesced under the force of gravity to form our solar system. As these materials are pulled together and become increasingly dense, they increase their spin rate—much as an ice skater pulling in her arms increases her rate of rotation, thus preserving angular momentum. The increased spinning motion counteracts part of the attraction of gravity, pulling particles outward, forming a flat disc shape. Much of the dust and small particles of rock eventually coalesced into planets. This helps explain why the planets in our solar system orbit in similar planes. Featured Scientists: Scott J. Kenyon, Ph.D., Ursula B. Marvin, Ph.D., and Sarah T. Stewart, Ph.D.
Science as Inquiry, 9-12 Standards: Formulate and revise scientific explanations and models using logic and evidence.
History and Nature of Science, 9-12 Standards: Nature of scientific knowledge: Science is a unique way of knowing due to its use of empirical standards, logical arguments, and skepticism. Scientists strive for the best possible explanations about the natural world.