Learner Express: Modules for Teaching and Learning
Following the invention of the telescope in 1609, the Moon's craters could be observed close up. Scientist Britt Argow and teacher Joe Reilly ask, "How are the craters on the Moon formed, and why do they exhibit the same nearly circular shape?" Planetary scientist, Prof. Sarah T. Stewart at Harvard University, throws a candlepin ball from the roof of the Earth and Planetary Sciences lab into a sandpit. This illustrates how the crater formed at impact is much larger than the projectile. Most craters are round because the energy of the impact causes shock waves, which spread equally in all directions, digging a much bigger hole than the size of the impactor alone. In planetary collisions, the projectile is nearly always destroyed on impact. Run Time: 00:02:04
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.