A
ABRASION - the scraping away of the first layer of something
ABSOLUTE BRIGHTNESS - how the stars would shine, if all the stars were the same distance from our eyes on Earth 
ABSOLUTE MAGNITUDE - brightness of stars when observed from a measured distance, how bright a star actually is

ACCELERATION - rate of change of velocity, increasing speed

AFRICA - a continent, south of the Mediterranean Sea 

ALBEDO - the amount of light reflected by an object, reflective

ALTITUDE - the angle between the celestial horizon and celestial objects

ANGLE - the space or figure formed between two lines or surfaces that meet

ANTARCTICA - the continent mainly within the Arctic Circle

APHELION - the point in the orbit of a planet or other body where it is farthest from the Sun

APOGEE - the point in the orbit of the Moon or other satellite where it is farthest from the Sun

APPARENT BRIGHTNESS - how the stars shine as seen from Earth

APPARENT MAGNITUDE - the brightness of a star or other celestial objects as seen from the Earth

ASIA - the largest of the continents extending from Europe to the Pacific

ASSOCIATION - a group of stars with nearly the same physical characteristics, indicating that they probably had the same origin

ASTEROID - a small body in orbit around the sun, usually between the orbit of Mars and Jupiter; a minor planet

ASTROLOGY - the study of the supposed influence of stars on human affairs

ASTRONOMER - a scientist that stories objects in outer space

ASTRONOMY - the branch of science that deals with the location, motion, and nature of objects in space

ASTRONAUT - a person that is trained to travel in a spacecraft

ATLAS - a book of maps

ATMOSPHERE - gaseous mass that envelopes a celestial body

ATTRACTION - to be pulled together by any force

AUSTRALIA - a continent and a country between the Pacific and Indian oceans

AUTUMNAL EQUINOX - point on the celestial equator where the Sun crosses it, the first day of autumn

AXIS - a line through the center of an object, around which it rotates when spinning 

AZIMUTH - the angle measured eastward along the celestial horizon between the north point and the vertical circle through a give object 


Africa
B
BARRED SPIRAL - a spiral galaxy having two arms extending from each end 

BAY - part of a sea or lake extending into land

BEACH - almost flat shore of sand or little stones

BINARY STAR - two stars in close proximity that affect each other

BLACK HOLE - a hypothetical celestial body with a small diameter and intense gravitational field that is held to be a collapsed star

BRIGHTNESS - the quality or state of being bright

Beach
C
CARBON DIOXIDE - a gas that humans emit when they breathe out; gas found in the bubbles in a carbonated soft drink. 

CARTOGRAPHY - the study of map drawing

CELESTIAL EQUATOR - the great circle on the celestial sphere mid-way between the celestial poles, reflects Earth's equator

CELESTIAL SPHERE - the sphere of infinite radius with center at the eye of the observer

CENTRIFUGAL - direction away from the center or axis

CENTRIPETAL FORCE - force directed toward a center of curvature

CHANNEL - the bed of a stream or river; passage for liquids; a groove

CHART - an outline map for showing special information

CHROMOSPHERE - gaseous envelop outside the photosphere; appears to have areas of color

CIRCULAR - round 

COMET - a body that orbits around the Sun

COMPASS - an instrument for showing directions, consisting of a needle that points to the north magnetic pole, which is near the North Pole

CONDENSE - make dense; become compact

CONJUNCTION - the apparent meeting of two or more celestial objects in the heavens

CONSTELLATION - a grouping of stars named for a mythical figure, animal, or inanimate object, there are 88 constellations

CONTINENT - a main land mass

CONTOUR - an outline 

CONTOUR INTERVAL - equal lines of elevation

COPERNICAN SYSTEM - the Sun as the center, planets revolve around the Sun

CORONA - Sun's atmosphere, only can be seen during a total solar eclipse

COSMOLOGY - the study of the universe and its evolution

COUNTRY - land; region

CRATER - a depression


channel
D
DAY - the time in which the Sun is above the horizon 

DESERT - a barren, wasteland of sandEARTH - the planet on which we live
moving away from a central

DISTANCE - the measure between the centers of two objects


desert
E
EARTH - the planet on which we live

EAST - the point on the horizon where the sun rises

ECCENTRICITY - off-centered orbit, not circular

ECLIPSE - the phenomenon of one body shutting off all or part of the light of another, or by an opaque body passing into the shadow of another opaque body

ELECTROMAGNETIC SPECTRUM - family of radiations that includes light, radio waves, infrared and ultraviolet light,X-rays, and gamma rays

ELEVATION - altitude or height

ELLIPTICAL - shaped like an ellipse

ELLIPSE - oval, not circular

ELLIPSOIDAL GALAXY - oval, clustering of stars

EROSION - to wear away by natural means

EQUATOR - an imaginary line around the Earth with equal distance between the north and south poles

EQUINOX - when the Sun crosses the equator and day and night are everywhere of equal length

EROSION - eating away; worn away

EUROPE - a continent extending from Asia to the Atlantic Ocean

EVOLUTION - the process by which something develops gradually into a different form

EXPANDING UNIVERSE - all parts of the universe are moving away from a central


earth
F
FALL - season of the year between summer and winter; autumn

FOREST - trees and undergrowth covering a large area

FULL MOON - the phase of the Moon when the visible disk is fully illuminated; Moon is at opposition


forest
G
GALAXY - a large collection of stars, dust, and gas in space; a system of millions or billions of stars held together by gravity

GAS GIANTS - refer to the planets of Jupiter, Saturn, Uranus, and Neptune; composed of gases and not solid like the terrestrial planets

GAMMA RAY - a quantity of high-energy radiation emitted from the nucleus of a radioactive atom

GEOGRAPHER - person who uses the skills of map reading in the majority of their job

GEOGRAPHY - the scientific study of the Earth's surface features

GEOLOGIC - dealing with rocks

GIBBOUS - the phase of the Moon or a planet between quarter and full

GLACIER - a river of ice moving very slowly

GLOBE - an object shaped like a ball with a map of the Earth on it

GRAVITATION - the force of gravity

GRAVITATIONAL ATTRACTION - being attracted by gravity

GRAVITY - the attractive force which masses exert on each other

GREAT CIRCLE - the largest circle that can be drawn on a sphere

GREENWICH MERIDIAN - the prime meridian through Greenwich, England

GREGORIAN CALENDAR - the present calendar introduced by Pope Gregory XIII
H
HARVEST MOON - the full Moon nearest the autumnal equinox

HELIOCENTRIC UNIVERSE - a theoretical universe with the Sun at the center

HELIUM - a light colorless gaseous element

HYDROGEN - a colorless odorless tasteless gaseous element, the lightest substance known, combining with oxygen to form water

HYDROSPHERE - the water "envelope" on the surface of Earth


harvest moon
I
ICE - frozen water

INERTIA - the property of matter that resists a change in its motion

INNER PLANETS - the planets close to the Sun including Mercury, Venus, Earth, and Mars. 

INNER PLATE - away from the plate boundaries

INTERVAL - a time between two events or parts of action


ice
J
JULIAN CALENDAR - a solar calendar introduced by Julius Caesar

K
KEPLER'S LAW - three laws of planetary motion stated by Johannes Kepler

KELVIN - an absolute scale of temperature; 0°C + 273°K, mathematically derived formula where at -273°C = 0°K is the lowest point where molecules can still move
L
LAKE - a large body of water completely surrounded by land

LAND - the solid part of the Earth's surface

LANDFORM - refers to different type of shapes that can be created on the surface of the Earth

LANDSCAPE - the scenery of an inland area

LATERITE - soil that has been leeched of most of its minerals

LATITUDE - angular distance north or south from the Earth's equator

LEAP YEAR - a calendar year with 366 days

LEGEND - a story handed down from the past

LIFE - being alive, the ability to function and grow

LIGHT - electromagnetic radiation visible to the eye

LIGHT YEAR - the distance light travels in one year; about 9.6 trillion kilometers

LITERATURE - writings

LONGITUDE - angular distance measured on a great circle, measured from a predetermined point (Greenwich, England)

LUNAR ECLIPSE - an eclipse of the Moon


lake
M
MAGNETIC FIELD - the force created by magnetism

MAGNITUDE - an arbitrary number to indicate the brightness of an object

MAP - a representation of the Earth's surface

MARTIAN - a fictional "living" being that was born on Mars

MASS - the quantity of matter a body contains

MERIDIAN - a great circle on the earth through the terrestrial poles

METEOR - describes the phenomenon associated with the collision of a large or small particle from space and the Earth's atmosphere

METEORITE - a fallen meteor, a fragment of rock or metal reaching Earth's surface from outer space

METEOROID - a body moving through space, of the same nature as those that become visible as meteors when they enter Earth's atmosphere

MILKY WAY - a faint band of light around the sky, composed of a vast number of stars and interstellar matter

MOON - a satellite that orbits a planet, due to gravitational attraction

MOONQUAKE - the shaking of the Moon like an earthquake 

MOUNTAIN - a mass of land that rises to a great height, especially of over a thousand feet


milky way
N
NADIR - the point opposite the zenith, a point overhead

NAVIGATION - the process of directing the course of ships

NEBULA - a gas or dust cloud in space

NEUTRON STAR - a collapsed star

NEW MOON - the phase of the Moon when it is in conjunction with the Sun

NEWTON'S LAW OF MOTION - refers to 3 laws that describe physical motion developed by Sir Isaac Newton

NIGHT - the dark hours between sunset and sunrise

NORMAL SPIRAL - a spiral galaxy with a nucleus from which arms extend; not a barred spiral

NORTH - to the left of a person standing east where the sun rises

NORTH AMERICA - the northernmost continent of the Western hemisphere

NORTHERN - of or in the north

NORTHERN HEMISPHERE - the northern portion of the Earth from the equator to the north pole


north america
O
OBSERVATION - the act, habit, or power of seeing and noting

OCEAN - the sea surrounding the continents of Earth

OPEN CLUSTER - a loosely formed group of stars; a galactic cluster

ORBIT - the part of the body in revolution around another body or bodies

OUTER SPACE - out of the Earth's atmosphere

OZONE LAYER - a layer of the Earth's atmosphere; the chemosphere


ocean
P
PARALLAX - the apparent displacement of an object when viewed from two different points

PEDALFER - soil that contains aluminum and iron

PEDOCAL - soil that contains calcium

PENINSULA - piece of land almost surrounded by water, or extending far out into the water

PERIGEE - the point in the orbit of a satellite where it is nearest to the Earth

PERIHELION - the point in the orbit of a planet or comet where it is nearest to the Sun

PHASES OF THE MOON - changes in the apparent shape of the illuminated portion of the Moon or a planet

PHOTO - a picture taken by photographic means

PHOTOSPHERE - sphere of light or radiance; the luminous visible surface of the Sun

PHYSICAL - of the body, physical fitness

PHYSICIST - a scientist that studies various physical phenomena 

PLAIN - a flat stretch of land

PLANET - a "wanderer" one of nine bodies in orbit around the Sun

PLANETARIUM - a projector that throws a reproduction of the sky onto the inside of a spherical dome to show the positions and motions of stars, planets, and other bright objects

PLANETESIMALS - one of the minute bodies that hypothetically was an original constituent of the Solar System

PLANETOID - a minor planet, an asteroid

PLASMA - a state of matter, highly ionized

POEM - a composition in verse

POLITICAL MAP - artificial boundaries between countries

POSITION - the way in which a thing or its parts are placed or arranged


planet
Q
QUADRANGLE - a geometric figure with four corners

quadrangle
R
RAIN - condensed moisture of the atmosphere falling in separate drops

RED GIANT - a large, cool star

RED SHIFT - a doppler shift toward the red end of the spectrum of most galaxies; basis for the theory of the expanding universe

REFLECT - to throw back

RELATIVE BRIGHTNESS - comparing stars which seems to shine the most

RELIEF - ease given by reduction or removal of pain or anxiety or a burden

RESOURCE - something in which someone can turn to for help or support or to achieve ones purpose

RETROGRADE MOTION - the apparent east to west motion of a planet or comet; opposite to direct motion

REVOLUTION - the motion of one body around another

REVOLVE - to turn or cause to turn around

RING - a circle of gas sounding the gas planets

RIVER - a large natural stream of water flowing in a channel

RIVER EROSION - erosion  caused by a river

ROCK - the hard part of the Earth's surface, underlaying the soil

ROTATE - to revolve or cause to revolve

ROTATION - the turning of a body about an axis

ROUND - having a curved shape or outline like a circle


rain
S
SATELLITE - a body that revolves around a larger body; a moon

SATELLITE PHOTOGRAPH - a picture taken from an orbiting vehicle

SCALE - the pan of a balance

SEA LEVEL - the level corresponding to that of the surface of the sea halfway between high and low water

SEASON - a section of the year with distinct characteristics of temperature and rainfall

SHOOTING STARS - a comet

SOIL - the loose upper layer of Earth where plants grow 

SOLAR ECLIPSE - the assemblage of planets, satellites, and other bodies under the gravitational influence of the Sun

SOLAR SYSTEM - the Sun with the heavenly bodies that revolve around it

SOLAR WIND - a radial flow of particles and radiation from the Sun

SOLSTICES - to points on the ecliptic where the Sun's declination is greatest

SOUTH - the point or direction opposite north 

SOUTH AMERICA - a continent in the southern Western Hemisphere

SOUTHERN HEMISPHERE - the half of the Earth between the equator and the south pole

SPACE - the boundless expanse in which all objects exist and move

SPACE SUIT - a sealed pressurized suit allowing the wearer to leave a spacecraft and move about independently in outer space

SPHERICAL - shaped like a sphere

SPECTRAL CLASS - the classification of a star from the appearance of the lines in its spectrum

SPIRAL GALAXY - a galaxy with a nucleus and spiral arms

SPRING - the season between fall and summer

SPRING BALANCE - a way to measure weight

SPRING TIDE - an exceptionally high tide produced by the reinforcement of solar and lunar tides

STAR - a self-luminous nearly spherical mass of gas

STAR MAP - a chart showing positions and magnitudes of stars

SUMMER - a season when the Sun's rays directly hit that surface of the Earth, the hottest time of the year

SUN - the star that is the gravitational center of the Solar System

SUNSPOT - a dark spot seen on the disk of the Sun; dark by contrast with the hotter photosphere

SUPERNOVA - an exploding star much more luminous than the normal nova

SURFACE - the uppermost area of something

SYZYGY - the lining up of three celestial bodies; conjunction or opposition


space
T
TELESCOPE - an instrument for observing objects at distance either visually or by other means

TEMPERATE - not very hot, not very cold

TERRESTRIAL PLANETS - planets whose composition is made of rock
TILT - being in a slanted position

TOPOGRAPHIC MAP - a map that shows the shape of the land surface 

TOPOGRAPHY - the accurate and detailed description of places

TOTAL ECLIPSE - an eclipse of the Sun, Moon, or star where the light is completely cut off

TWINKLE - the changing brightness and color of stars due to the Earth's atmosphere

TYCHONIC SYSTEM - a model of the universe proposed by Tycho Brahe


telescope
U
UNIVERSE - the cosmos, everything that is out there

universe
V
VALLEY - long land between hills or mountains 

VEGETATION - plant life; growing plants

VERIFY - to prove

valley
W
WATER - a colorless odorless tasteless liquid that is a compound of oxygen and hydrogen

WAVE - a ridge of water moving along the surface of the sea

WEIGHT - how heavy a thing is

WEST - the point of the horizon where the sun sets

WHITE DWARF - a star that has about the same mass, but much smaller diameter, as ordinary star, a white star several magnitudes below the main sequence

WIND - a current of air occurring naturally in the atmosphere or put in motion by the movement of something through the air 

WINTER - when the rays of the Sun are indirect; the coldest of all the seasons 

WORLD MAP - a map of the world


wave
X
Y
Z
ZENITH - the point overhead

ZODIAC - an imaginary belt in the heavens