Term
|
Definition
| Our universe began about 13.7 billion years ago with a cosmic explosion. |
|
|
Term
|
Definition
| The idea that the solar system originated from a diffuse, slowly rotating cloud of gas and find dust (nebula) that contracted under the force of gravity and eventually evolved into the Sun and planets. |
|
|
Term
|
Definition
| One of the more than 10,000 small celestial bodies orbiting the Sun, most of them between the orbits of Mars and Jupiter. |
|
|
Term
|
Definition
| Any of the several tiny objects of the outer solar system (Pluto) that are composed of a frozen mixture of gases, ice, and rock and that orbit the Sun in an unsual pattern that sometimes brings them closer to the Sun than Neptune. |
|
|
Term
|
Definition
| According to the nebular hypothesis, a disk of gas and dust that surrounded the prot-Sun from which the planets of the solar system formed. |
|
|
Term
|
Definition
| The dense central part of Earth below the core-mantle boundary, composed principally of iron and nickel. |
|
|
Term
|
Definition
| The thin outer layer of Earth, averaging from about 8km thick under the oceans to about 40km thick under the continents, consisting of relatively low-density that melt at relatively low temperatures. |
|
|
Term
|
Definition
| The region that forms the main bulk of Earth, between the crust and the core, containing rocks of intermediate density, mostly compounds of oxygen with magnesium, iron, and silicon. |
|
|
Term
|
Definition
| Any of the four inner planets of the solor system (Mercury, Venus, Earth, And Mars) that form dense matter close to the Sun, where conditions were so hot that most of their volatile materials boiled away. Also called Earthlike planets. |
|
|
Term
|
Definition
| gaseous with rockey cores (Jupiter, Saturn, Uranus, Neptune) |
|
|
Term
|
Definition
| any process in which a mixture of materials separates out partially or completely into its constituent parts, as in the cooling and solidification of a magma into two or more different rock types or in the gradual separation of an originally homogeneous earth into crust, mantle, and core. |
|
|
Term
|
Definition
| To find "Earth-like" planets and estimate their number in our galaxy. |
|
|
Term
|
Definition
| The weak, ductile layer of rock that constitutes the lower part of the upper mantle and over which the lithospheric plates slide. |
|
|
Term
|
Definition
| The large-scale movements of continents across Earth's surface driven by the plate tectonic system. |
|
|
Term
|
Definition
| A boundary between lithospheric plates where the plates move towards each other and one plate is recycled into the mantle. |
|
|
Term
|
Definition
| A boundary between lithospheric plates where two plates move apart and new lithsopheric is created. |
|
|
Term
|
Definition
| A chain of volcanic islands formed on the overriding plate at a convergent boundary by megma that rises from the mantle as water released from the subducting lithospheric slab causes fluid-induced melting. |
|
|
Term
|
Definition
| The region of influence of a magmentized body or and electric current. |
|
|
Term
|
Definition
| The detailed history of Earth's magnetic field reversals as determid by measuring the thermoremanent magnetization of rock samples whose ages are unknown. |
|
|
Term
|
Definition
| The layer Earth extending from the core-mantle boudary to the inner core, at depths of 2890 to 5150 km, composed of molten iron and nickel and minor amounts of lighter elements, such as oxygen or sulfer. |
|
|
Term
|
Definition
| A supercontinent that coalescode in the late Paleozoic era and comprised all present continents, then began to brake up in the Mesozoic era. |
|
|
Term
|
Definition
| The theory that describes and explains the creation and destruction of Earth's lithsopheric plates and their movement over Earth's surface. |
|
|
Term
|
Definition
| The mechanism by which new oceanic crust is formed at a spreading center on the crust of a mid-ocean ridge. As two plates move apart, magma wells up into the rift between them to form new crust, which spreads laterally awa from the rift and is replaced continually by newer crust. |
|
|
Term
|
Definition
| The sinking of oceanic lithospheric beneath overriding oceanic of continental lithospheric at a convergent plate boundary. |
|
|
