In evaluating Terra Nova scores for l999, I found that at least 75% of my 5th graders experienced difficulty passing a test explaining the forces of gravity that control earth's movement. A TN Curriculum Framework Content for Science Standards for Grades 3-5 is interactions of matter and energy shape our world. The Science Curriculum states that students must understand that living things contribute energy to and take energy away from non-living surroundings causing changes in both. The interactions of matter and energy are subject to accepted physical laws. Learning expectations for these standards will include the following: The student will work in a cooperative group to discover about earth's shape and gravity using a globe, a set of questions, and library resources; define the terms: rotate, revolve, and orbit; demonstrate what motion of the earth causes night and day; describe how the length of the year on the earth is determined; be able to name the 9 planets of the Solar System and know basic important characteristics that make each one different from the other. This unit will provide different strategies for teaching about the solar system.