Lesson 17

the study of planets in relation to one another

the layer of dense rock and metal oxides that lies between the molten core and the planet's surface

a pressure wave; a type of seismic wave produced in earth by the compression of material

a shear wave; a type of seismic wave produced in earth by the lateral motion of material

a material with the properties of a solid but capable of flowing under pressure

earth's first air

the gases outgassed from a planet's interior; rich in carbon dioxide

the process by which a carbon dioxide atmosphere traps heat and raises the tempenture of a planetary surface.

the gradual increase in the surface temperature of earth caused by human modifications to earth's atmosphere

the constant destruction and renewal of earth's surfaceby the motion of sections of crust

a long, straight, deep valley produced by the separation ofcrustal plates

one of the undersea mountain ranges that pushes up from the seafloor in the centre of the oceans

dark igneous rock that is characteristic of solidified lava

a region of planetary crust where a tectonic plate sides downward

a long range of mountains formed by the compression of a planet's crust

one of the lunar lowlands filled bys successive flows of dark rock

the ratio of light reflected from an object divided by the light that hits the object. Albedo equals zero (0) for perfectly black and one (1) for perfectly white

the dividing line between daylight and darkness on a planet or moon

a porous rock formed by solidified lava with trapped bubbles

rock of aluminum and calcium silicates found in the lunar highlands

rock compsed of fragments of earlier rocks bonded together

the theory that the moon and earth formed when a rapidly rotating protoplanet split into two pieces

the theory that earth and the moon condensed from the same cloud of material in roughly their present oribtal relationship

the theory thatthe earth's moon formed elsewhere in the solar nebula and was later captured by earth

the theeory that the moon formed from debris ejected during a collision between earth and a large planetesimal

pulverized rock scattered by meteorite impacts on a planetary surface

ejecta from meteorite impacts forming white streamers radiating from some lunar creatures

an impact crater formed by debris ejected from a larger impact

large impact feature (crater) containing two or more concentric rims formed by fracturing of the planetary crust

large areas of molten rock that solidified such as on the surface of the moon

a curved cliff such as those found on Mercury

on Venus, large, round geological faults in the crust caused by the intrusion of magma below the crust

avolcano formed by successive lava and ash flows. Such volcanoes have steep sides and, on Earth, are found along subduction zones.

wide, low profile volcanic cone produced by highly liquid lava

soil at or below the freezing point of water for two or more years; usually found in polar capsor within the soil at high latitudes or high altitudes

geological feature produced by the rapid motion of floodwaters; usually applied to features on Mars

a system of dry drainage channels on Mars that resembles the beds of rivers and tributary streams on earth