Introduction to Earth and Space Science

This course (designed for grade 8, 9, or 10) introduces students to key science concepts that provide a foundation for further study in a variety of other science disciplines. Throughout the course, previously studied physical and life sciences concepts are applied, reinforced, and extended within the context of Earth and space sciences. There are three main organizing themes from which to develop standards-based learning cycle lessons:

• The universe
• Earth systems
• Nature of energy

The Universe

• The field of astronomy has progressed from early scientific achievements (Ptolemy's mathematical model of an Earth-centered universe, Copernicus's heliocentric model, Galileo's telescopes, and Brahe's observational data, which led to Kepler's laws) to more modern endeavors such as the space race, the first moon landing, and the International Space Station.
• Advances in technology have improved understandings of celestial objects and events, but information about deep space and deep time continues to be literally and figuratively beyond the reach of modern science.
• The laws of matter apply across distance and time. Through laboratory experiments and observations of certain phenomena, scientists have determined that the motion of the Earth, the sun, and all celestial bodies is governed by gravitation and inertia. This results in the rotation and revolution of everything from the smallest asteroid to the largest black hole.
• The universe is estimated to be over 14 billion years old. Currently, astronomers conclude that the universe was created from a cataclysmal event referred to as the big bang. Evidence for the big bang includes cosmic background radiation and red shifts observed from very distant galaxies.
• The universe is vast. Billions of stars populate the mostly empty space of the universe. These stars vary in size, age, and color. The sun is a middle-aged, medium-sized, yellow star.
• All stars, including the sun, are powered by enormous amounts of energy released by the nuclear fusion occurring in their cores.

Earth Systems

• Biogeochemical cycles circulate energy and material through the Earth system. These cycles regulate the Earth's climate and result in the dynamic nature and appearance of the Earth's surface. Cycles include, but are not limited to, the hydrologic cycle, the carbon cycle, and the rock cycle.
• The hydrologic cycle moves water throughout seven main water reservoirs: the ocean, atmosphere, surface water, groundwater, biosphere, lithosphere, and glaciers. The ocean is the largest reservoir, holding 97% of all of the Earth's water.
• Temperature and chemical differences in the ocean cause density differences in the water that contribute to the complex deep-water circulation patterns of the ocean. These ocean processes, along with wind, result in short-term weather phenomena. In contrast, long-term weather patterns, particularly temperature and precipitation, determine a region's climate. Factors such as solar energy, ocean processes, winds, and geographical features (e.g., latitude and altitude) also impact climate.
• The carbon cycle moves carbon throughout four main carbon reservoirs: the biosphere, the atmosphere, the ocean, and the lithosphere.
• The rock cycle, driven by tectonic activity, continually creates, breaks down, and transforms rock. Timing and location prevent many rocks from moving cleanly through the cycle.
• Density differences caused by the convective heat flow within the Earth's interior drive the process of plate tectonics. Data supporting the theory of plate tectonics include earthquake and volcanic activity along plate margins, seafloor spreading, fossils and landforms that appear to be the same but are ocean apart, and results from dating techniques.

Nature of Energy

• Electromagnetic radiation is produced when electrons in the excited state emit wavelengths of energy as they return to their original ground states. Depending on the atom type, the resulting radiation takes one of the following forms: gamma rays, X-rays, ultraviolet, visible light, infrared, microwave, or radio.
• Electromagnetic radiation effectively travels in space because it does not require matter to be transmitted. However, only certain wavelengths of electromagnetic radiation from space reach the Earth's surface. These include visible light, radio, and some ultraviolet.
• Solar energy supplies nearly all of the energy necessary for circulating the ocean and atmosphere. Energy is transferred between the Earth's surface and the atmosphere by radiation, convection, and conduction. This energy transfer is influenced by dynamic processes such as cloud cover, Earth's rotation, and the positions of the mountain ranges and ocean.
• The convective heat responsible for plate tectonics is powered by the heat from the decay of radioactive materials deep inside the Earth as well as by residual heat from the formation of the Earth.
• Tectonic activity produces mechanical waves of energy that travel on the Earth's surface and through the Earth's interior. Primary (P) waves are compression waves, while secondary (S) waves are shear waves. The propagation of these waves is affected by the physical properties of the materials they encounter.
• The Earth contains a finite amount of energy and resources. With a human population of more than 6 billion people, it is increasingly evident that humans have the ability to positively or negatively impact Earth's climate, atmosphere, and living systems.