| conjunction |
in astronomy and astrology, the lining up of two or more celestial bodies, esp. the sun and a planet, along a line as viewed from Earth. [1/4 definitions] |
| Copernican system |
the theory, first held by Copernicus, that the earth and other planets revolve around the sun. |
| core |
the center part of any round, solid object. The center of the earth is called its core. [1/4 definitions] |
| Coriolis force |
a force held to be responsible for the straying off course of a falling object toward a rotating body such as the earth. |
| cosmic |
existing or originating outside the earth. [1/3 definitions] |
| cosmic noise |
interference from radio waves beyond the earth; galactic noise. |
| cosmography |
the science, or a particular description, of the physical arrangement of the universe and the earth. |
| cosmos |
the universe beyond the earth. [1/4 definitions] |
| crater |
a similar depression in the surface of the earth or other heavenly bodies caused by the impact of falling meteorites or the explosion of a mine or bomb. [1/3 definitions] |
| crust |
the outer layer of Earth, another planet, or a moon. [1/5 definitions] |
| day |
a unit of time equal to twenty-four hours, or the time it takes the earth to rotate once on its axis. [1/5 definitions] |
| Dead Sea |
a large salt lake between the countries of Israel and Jordan. The Dead Sea lies at about 1300 feet below sea level, which makes it the lowest known place on the surface of the earth. |
| diastrophism |
the process by which the surface of the earth changes in shape and levels because of movements of the earth's crust. [1/2 definitions] |
| didymium |
any mixture of rare-earth metals used commercially. [1/2 definitions] |
| dike |
a ditch, or bank of earth dug from a ditch, as to channel irrigation. [1/6 definitions] |
| dirt |
loose earth or soil. [1/2 definitions] |
| D layer |
the lowest layer of the ionosphere, about forty-five to eighty miles above the earth. |
| dysprosium |
a rare-earth metal chemical element of the lanthanide series that has sixty-sixprotons in each nucleus. (symbol: Dy) |
| earth |
all of the people who live on Earth. [1/4 definitions] |
| earthbound |
limited or confined to earth or earthly matters. [2/3 definitions] |
| earthen |
made up of earth, soil, or dirt. [1/2 definitions] |