Objects in the sky have patters of movement. The Sun, for example, appears to move across the sky in the same way every day, but its path changes slowly over the seasons. The moon moves across the sky on a daily basis much like the sun. The shape of the moon seems to change from day to day in a cycle that lasts about a month. The sun provides the light and heat necessary to maintain the temperature of the Earth.
Earth materials are solid rocks and soils, liquid water, and the gases of the atmosphere.
These varied materials have different physical and chemical properties. These properties make them useful, for example, as building materials, as sources of fuel, or for growing the plants we use as food. Earth materials provide many of the resources humans use. Soils have properties of color and texture, capacity to retain water and ability to support the growth of many kinds of plants, including those in our food supply. Other Earth materials are used to construct buildings, make plastics and provide fuel for generating electricity and operating cars and trucks.