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. The surface of the Earth changes. Some changes are due to slow processes, such as erosion and weathering, and some changes are due to rapid processes such as landslides, volcanoes, and earthquakes. Fossils provide evidence about the plants and animals that lived long ago and nature of the environment at that time.