The National Science Education Standards (1995) provide a vision of science literacy for all students in our nation's schools. The content standards of NSES outline what students ought to know, understand, and be able to do at various stages of their K-12 education. Inquiry should play a central role in developing students' understandings. The Standards are a call for action from individuals and organizations at all levels of the system. Thus, standards for science teaching, professional development of science teachers, assessment, science education programs, and science education systems are incorporated into the Standards as well. Responsibility for providing the support necessary to attain science literacy falls on everyone involved in the science education system. The K-4 Earth science standards target students' understandings of properties of Earth materials, objects in the sky, and changes in the Earth and sky. Science lessons for students at these grade levels should focus on observing the objects and materials in their environment; distinguishing one from another; noting their properties, patterns, and changes; and developing explanations of how things became what they are. Activities include observing changes in weather and in the positions of objects in the day and night sky, as well as examining the properties of Earth materials, such as soil, rocks, water, and fossils. In grades 5-8, students build upon understandings gained through observation in earlier grades to develop an understanding of the Earth and solar system as a set of closely related systems. The rock and water cycles provide an opportunity to examine interactions between the geosphere, hydrosphere, atmosphere, and biosphere. Earth history can be examined to gather evidence about the CO-evolution of Earth's main features: the distribution of land and sea, crustal features, atmospheric composition, global climate, and populations within the biosphere. The study of earthquakes and volcanoes provides evidence necessary to better understand the nature and features of the dynamic geosphere. Students should also begin to construct mental models that explain the visual and physical relationships among objects within the solar system. Earth and space science standards within grades 9-12 continue the system's approach by focusing on matter, energy, crustal dynamics, geochemical processes, and the expanded time scales needed to understand changes within the Earth system. Students in these grades should engage in examinations of the energy sources and processes which drive geochemical cycles within and on the planet. They are also ready to comprehend more abstract and long-term phenomena, including explanations for plate tectonics, the evolution of life, and the solar system.

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