aa - ansa slow-moving type of lava that hardens to form rough chunks; cooler that pahoehoe
absolute age - ansthe age of a rock given as the number of years since the rock formed
absolute brightness - ansThe brightness a star would have if it were at a standard distance from Earth.
aftershock - ansan earthquake that occurs after a larger earthquake in the same area
anticline - ansan upward fold in rock formed by compression of Earth's crust
apparent brightness - ansthe brightness of a star as seen from Earth
asthenosphere - ansthe soft layer of the mantle on which the lithosphere floats
axis - ansAn imaginary line that passes through Earth's center and its North and South Poles.
basalt - ansa rock that makes up much of the ocean floor
Big bang - ansThe initial explosion that resulted in the formation and expansion of the universe
binary star - ansa star system with two stars
black hole - ansAn object whose gravity is so strong that nothing, not even light, can escape
cast - ansa type of body fossil that forms when crystals fill a mold or sediments wash into a mold and harden
into rock
, chromosphere - ansThe middle layer of the sun's atmosphere
climate - ansaverage, year-after-year conditions of temperature and precipitation in a particular region
compression - ansthe type of stress that occurs when an object is squeezed
conduction - ansthe direct transfer of heat from one substance to another substance that it is touching
continental drift - ansthe hypothesis that states that the continents once formed a single landmass, broke up,
and drifted to their present locations
convection - ansthe transfer of heat by the movement of a fluid
convection current - ansthe movement of a fluid, caused by differences in temperature, that transfers heat
from one part of the fluid to another
convergent boundary - ansa plate boundary where two plates move tward each other
coriolis effect - ansThe way Earth's rotation makes winds in the Northern Hemisphere curve to the right and
winds in the Southern Hemisphere curve to the left.
corona - ansThe outermost region of the sun's atmosphere.
Cosmic background radiation - ansThe electromagnetic radiation left over from the big bang
crater (volcano) - ansa bowl-shaped opening at the top of a volcano