| A | B |
|---|
| astronomy | the scientific study of the universe; It includes the observation and interpretation of celestial bodies and phenomena. |
| atmosphere | the gaseous portion of a planet; the planet’s envelope of air; one of the traditional subdivisions of Earth’s physical environment |
| biosphere | all life on Earth; the parts of the solid Earth, hydrosphere, and atmosphere in which living organisms can be found |
| contour interval | on a topographic map, tells the distance in elevation between adjacent contour lines |
| contour line | line on a topographic map that indicates an elevation; Every point along a contour line has the same elevation. |
| core | the innermost layer of Earth, located beneath the mantle; The core is divided into an outer core and an inner core. |
| crust | the thin, rocky outer layer of Earth |
| Earth science | the name for all the sciences that collectively seek to understand Earth; It includes geology, oceanography, meteorology, and astronomy. |
| geology | the science that examines Earth, its form and composition, and the changes it has undergone and is undergoing |
| geosphere | layer of Earth under both the atmosphere and the oceans; It is composed of the core, the mantle, and the crust. |
| hydrosphere | the water portion of Earth; one of the traditional subdivisions of Earth’s physical environment |
| hypothesis | a tentative explanation that is tested to determine if it is valid |
| latitude | the distance north or south of the equator, measured in degrees |
| longitude | the distance east or west of the prime meridian, measure in degrees |
| mantle | the 2890-kilometer-thick layer of Earth located below the crust |
| meteorology | the scientific study of the atmosphere and atmospheric phenomena; the study of weather and climate |
| oceanography | the scientific study of the oceans and oceanic phenomena |
| system | any size group of interacting parts that form a complex whole |
| theory | a well-tested and widely accepted view that explains certain observable facts |
| topographic map | a map that represents Earth’s surface in three dimensions; It shows elevation, distance, directions, and slope angles. |
