Space

Front 1

moon phases

Back 1

one of the different apparent shapes of the moon as seen from Earth

Front 2

waning

Back 2

an object is decreasing, or growing smaller

Front 3

waxing

Back 3

an object is increasing, or growing larger

Front 4

New Moon

Back 4

The Moon's side that is not illuminated, but is facing the Earth

Front 5

Waxing Crescent

Back 5

This phase occurs when the visible Moon is partly but less than 1/2 illuminated by direct sunlight. Illumination is increasing.

Front 6

First Quarter

Back 6

1/2 of the moon appears illuminated by direct sunlight while the illuminated part is increasing.

Front 7

Waxing Gibbous

Back 7

The moon appears to be more than 1/2 but not fully illuminated by direct sunlight. Illumination is increasing.

Front 8

Full Moon

Back 8

The moon's illuminated side faces earth and appears as a fully-lighted disk.

Front 9

Waning Gibbous

Back 9

The moon appears to be more than 1/2 but not fully illuminated by direct sunlight. Illumination is decreasing.

Front 10

Last Quarter

Back 10

1/2 of the moon appears to be illuminated by direct sunlight. Illumination is decreasing.

Front 11

Waning Crescent

Back 11

The moon appears to be partly but less than 1/2 illuminated by direct sunlight. Illumination is decreasing.

Front 12

Crater

Back 12

A bowl-shaped cavity in the ground made by an impact or explosion.

Front 13

Geocentric

Back 13

A model of the universe in which Earth is at the center of the revolving planets and stars.

Front 14

Heliocentric

Back 14

A model of the solar system in which Earth and other planets revolve around the sun

Front 15

Core

Back 15

The central region of the sun, where nuclear fusion takes place.

Front 16

Nuclear Fusion

Back 16

The process by which hydrogen atoms join together in the sun's core to form helium.

Front 17

Radiation zone

Back 17

A region of very tightly packed gas in the sun's interior where energy is transferred mainly in the form of light.

Front 18

Convection zone

Back 18

The outermost layer of the sun's interior.

Front 19

Photosphere

Back 19

The inner layer of the sun's atmosphere that gives off its visible light; the sun's surface.

Front 20

Chromosphere

Back 20

The middle layer of the sun's atmosphere

Front 21

Solar wind

Back 21

A stream of electrically charged particles that emanate from the sun's corona

Front 22

Sunspot

Back 22

A dark area of gas on the sun's surface that is cooler than surrounding gases

Front 23

Prominence

Back 23

A huge, reddish loop of gas that protrudes from the sun's surface, linking parts of sunspot regions

Front 24

Solar flare

Back 24

An eruption of gas from the sun's surface that occurs when the loops in sunspot regions suddenly connect

Front 25

Astronaut

Back 25

A person who is trained to travel in a spacecraft

Front 26

Cosmonaut

Back 26

A Russian astronaut

Front 27

ISS (International Space Station)

Back 27

An internationally developed research facility, shared by space programs from 16 countries, that circles the earth in space so that experiments can be done.

Front 28

Satellite

Back 28

An artificial body placed in orbit around the earth or another planet in order to collect information or for communication

Front 29

Space probe

Back 29

An unmanned spacecraft which collects information about objects in space and sends it back to scientists on Earth

Front 30

Rocket

Back 30

A vehicle that burns fuel and shoots the flaming gases out one end (the engine) to move in the opposite direction

Front 31

Space Shuttle

Back 31

A rocket-launched spacecraft, able to land like an unpowered aircraft, used to make repeated journeys between the earth and earth orbit

Front 32

Launch Pad

Back 32

The platform area on which a rocket stands for launching

Front 33

Space race

Back 33

The competition between nations regarding achievements in the field of space exploration

Front 34

NASA

Back 34

An independent agency of the United States government responsible for aviation and spaceflight

Front 35

Space exploration

Back 35

The use of astronomy and space technology to explore outer space.

Front 36

Spin-off

Back 36

A business or organization developed out of or by members of another organization, in particular a subsidiary of a parent company that has been sold off, creating a new company

Front 37

Astronomy

Back 37

The study of the moon, starts, and other objects in space

Front 38

Axis

Back 38

An imaginary line that passes through Earth's center and the North and South poles, about which Earth rotates

Front 39

Rotation

Back 39

The spinning motion of a planet on its axis

Front 40

Revolution

Back 40

The movement of an object around another object

Front 41

Orbit

Back 41

The path of an object as it revolves around another object in space

Front 42

Calendar

Back 42

A system of organizing time that defines the beginning, length, and divisions of a year

Front 43

Solstice

Back 43

The two days of the year on which the sun reaches its greatest distance north or south of the equator

Front 44

Equinox

Back 44

The two days of the year on which neither hemisphere is tilted toward or away from the sun

Front 45

Aphelion

Back 45

The point in the orbit of a planet, asteroid, or comet at which it is furthest from the sun

Front 46

Perihelion

Back 46

The point in the orbit of a planet, asteroid, or comet at which it is closest to the sun

Front 47

Vernal equinox

Back 47

Marks the beginning of spring in the northern hemisphere

Front 48

Autumnal equinox

Back 48

Marks the beginning of fall in the northern hemisphere

Front 49

Ellipse

Back 49

An oval shape, which may be elongated or nearly circular

Front 50

Corona

Back 50

The outer layer of the Sun's atmosphere

Front 51

Terrestrial planets

Back 51

The name often given to the four inner planets: Mercury, Venus, Earth, and Mars

Front 52

Greenhouse effect

Back 52

The trapping of heat near Earth's surface by certain gases in the atmosphere

Front 53

Gas giant

Back 53

The name often given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune

Front 54

Ring

Back 54

A thin disk of small ice and rock particles surrounding a planet

Front 55

Solar system

Back 55

System of eight planets, including Earth, and other objects that revolve around the sun

Front 56

Galaxy

Back 56

A huge group of single starts, star systems, star clusters, dust, and gas bound together by gravity

Front 57

Mercury

Back 57

Smallest planet, closest to the Sun; does not have a true atmosphere; has a surface with many craters and high cliffs

Front 58

Venus

Back 58

Second planet from the Sun; similar to Earth in mass and size

Front 59

Earth

Back 59

Third planet from the Sun; has an atmosphere that protects life and surface temperatures that allow water to exist as a solid, liquid, and gas

Front 60

Mars

Back 60

Fourth planet from the Sun; has polar ice caps, a thin atmosphere, and a reddish appearance caused by iron oxide in weathered rocks and soil