(Encyclopedia) DeucalionDeucaliondy&oomacr;kāˈlēən [key], in Greek mythology, son of Prometheus and father of Hellen. When Zeus, angered by humanity's irreverence, flooded the earth, Deucalion,…
(Encyclopedia) equator, imaginary great circle around the earth, everywhere equidistant from the two geographical poles and forming the base line from which latitude is reckoned. The equator, which…
(Encyclopedia) Hopkins, William, 1793–1866, English geologist. Hopkins studied mathematics at Cambridge, and then supported himself as a private mathematics tutor. Many of England's best…
(Encyclopedia) tektitetektitetĕktīt [key], naturally occurring, silica-rich (65%–80% SiO2) glass resembling obsidian and sometimes shale, and is normally jet black to olive green. They appear as…
(Encyclopedia) geomorphology, study of the origin and evolution of the earth's landforms, both on the continents and within the ocean basins. It is concerned with the internal geologic processes of…
ENERGY FROM THE SUNINSIDE A NUCLEAR POWER STATIONRENEWABLE ENERGYGEOTHERMAL ENERGYFIND OUT MOREEverything we do takes energy, which we get from many different sources. Most of the energy on Earth…
(Encyclopedia) cycle, in astronomy, period of time required for the recurrence of some celestial event. The length of a cycle may be measured relative to the sun or to the fixed stars (see sidereal…
Impact craterDeath from spaceOther dinosaur extinction theoriesAbout 65 million years ago, at the end of the Cretaceous Period, the Earth was affected by major changes to its environment. Animal…
Because of its blood-red color (which comes from iron-rich dust), this planet was named for Mars, the Roman god of war. Mars is the fourth planet from the Sun, situated between Earth and Jupiter.…
Rocks are classified in three types based on how they are formed.Igneous rocks are formed when molten rock (magma) from within Earth cools and solidifies. There are two types: intrusive igneous…
