In its strictest sense, as used by geologists, the term Earth science is synonymous with Geology, the study of the solid part (Lithosphere) of the planet Earth. More commonly, however, the Earth sciences are thought to include the study of the Earth's other major divisions, the Atmosphere and Hydrosphere, as well as the planet's environment in space. Thus it commonly refers to broad, interrelated studies that encompass the solar system (Astronomy and Astrophysics), atmospheric phenomena (Meteorology), and water, both on land (Hydrologic Sciences) and in the sea (Oceanography), as well as the solid Earth.
One of the major concerns of geology is to discover the origin and nature of the raw materials of the Earth, Minerals. These naturally occurring inorganic substances make up aggregates called rocks--the solid portions of the Earth. Geology also studies the processes associated with volcanic activity (Volcano), dynamic earth movements (Plate Tectonics), Erosion And Sedimentation, And Weathering to achieve an understanding of the development of all parts of our planet.
Other forces that shape the Earth are studied by meteorologists and oceanographers whose respective disciplines--sometimes referred to as the twin sciences--are related in scope and focus. In addition to examining the chemical composition and physical properties of their respective spheres, each also examines the motions of air and water and their contributions to landform evolution. ocean currents are directly influenced by WINDS, and the processes that operate at the interface between ocean and atmosphere (ocean-atmosphere interaction) determine the weather as well as the climate.
In recent years, the scope of the Earth sciences has been further expanded to include what are collectively known as the environmental sciences--studies directed mainly toward environmental conditions that affect living organisms in a general way (ecology) and adversely (pollution, environmental).
The ultimate goal of the Earth sciences is to unravel the mystery of the origin and evolution of our planet. In working toward this, scientific disciplines and fields of study that encompass the space beyond the Earth's atmosphere are employed.
In astronomy, chemistry and physics are used to study the composition, physical properties, and motion of the moon and the Earth's other neighbors in space (astrochemistry; astrogeology), whereas biology is used to search for living organisms beyond Earth (life, extraterrestrial). Astronomy now contributes chemical and physical data on the behavior of atoms in unfamiliar circumstances, such as the cold of space and the interior of stars, as well as delving into subjects such as the nature of time, how objects move in space, and theories of the origin of the universe (cosmology).
Joseph S. Weisberg
Bibliography: Birkeland, P. W., and Larson, E. E., Putnam's Geology, 4th ed. (1982); Calder, Nigel, The Restless Earth (1972); Ferris, Timothy, Coming of Age in the Milky Way (1988); Gould, Joseph, et al., Earth Science (1985); Selby, M. J., Earth's Changing Surface (1985); Smith, David G., ed., Cambridge Encyclopedia of Earth Sciences (1982); Smith, Peter J., The Earth (1986); Weisberg, Joseph S., Meteorology: The Earth and Its Weather (1976); Young, Louise B., The Blue Planet (1984).