Astronomy Book Test 2012

Front 1

What are the regions of the electromagnetic spectrum?

Back 1

radio waves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays

Front 2

What are telescopes and how do they work?

Back 2

instruments that collect and focus light and other forms of electromagnetic radiation

Front 3

Where are most large telescopes located?

Back 3

Many large observatories are located on mountaintops or in space

Front 4

refracting telescope

Back 4

A telescope that uses convex lenses to gather and focus light.

Front 5

reflecting telescope

Back 5

A telescope that uses a curved mirror to collect and focus light.

Front 6

radio telescope

Back 6

A device used to detect radio waves from objects in space.

Front 7

How are stars classified?

Back 7

Characteristics used to classify stars include color, temperature, size, composition, and brightness.

Front 8

How do astronomers measure distances to the stars?

Back 8

Astronomers use a unit called the light-year to measure distances between the stars

Front 9

What is an H-R diagram and how do astronomers use it?

Back 9

The H-R diagram is a graph relating the surface temperatures and absolute brightnesses of stars. Astronomers use H-R diagrams to classify stars and to understand how stars change over time.

Front 10

constellation

Back 10

An imaginary pattern of stars in the sky.

Front 11

spectrograph

Back 11

An instrument that separates light into colors and makes an image of the resulting spectrum.

Front 12

apparent brightness

Back 12

The brightness of a star as seen from Earth.

Front 13

absolute brightness

Back 13

The brightness a star would have if it were at a standard distance from Earth.

Front 14

light-year

Back 14

The distance that light travels in one year

Front 15

parallax

Back 15

The apparent change in position of an object when seen from different places.

Front 16

Hertzsprung-Russell diagram

Back 16

A graph relating the surface temperatures and absolute brightnesses of stars.

Front 17

main sequence

Back 17

A diagonal area on an H-R diagram that includes more than 90 percent of all stars.

Front 18

nebula

Back 18

A large cloud of gas and dust in space, spread out in an immense volume.

Front 19

What is a star system?

Back 19

Most stars are members of groups of two or more stars, called star systems.

Front 20

What are the major types of galaxies?

Back 20

spiral, elliptical, and irregular

Front 21

binary star

Back 21

A star system with two stars.

Front 22

open cluster

Back 22

A star cluster that has a loose, disorganized appearance and contains no more than a few thousand stars.

Front 23

globular cluster

Back 23

A large, round, densely-packed grouping of older stars.

Front 24

galaxy

Back 24

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

Front 25

spiral galaxy

Back 25

A galaxy with a bulge in the middle and arms that spiral outward in a pinwheel pattern.

Front 26

Compare and contrast spiral and elliptical galaxies

Back 26

Both are large galaxies, but spiral galaxies mostly have young stars, whereas elliptical galaxies have mostly old stars.

Front 27

Compare and contrast spiral and irregular galaxies

Back 27

Both contain young stars, but spiral galaxies are much larger and have a pinwheel shape.

Front 28

elliptical galaxy

Back 28

A galaxy shaped like a round or flattened ball, generally containing only old stars

Front 29

irregular galaxy

Back 29

A galaxy that does not have a regular shape.

Front 30

universe

Back 30

All of space and everything in it.

Front 31

How does Earth move in space?

Back 31

Earth moves through space in two major ways: rotation and revolution.

Front 32

What causes the cycle of seasons on Earth?

Back 32

Earth has seasons because its axis is tilted as it revolves around the sun. The tilt relative to the sun changes the angle of sunlight received. Higher angles means more direct light which means warmer weather. The opposite is true for low angles of sunlight.

Front 33

axis

Back 33

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

Front 34

rotation

Back 34

The spinning motion of a planet on its axis.

Front 35

revolution

Back 35

The movement of an object around another object.

Front 36

orbit

Back 36

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

Front 37

solstice

Back 37

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

Front 38

equinox

Back 38

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

Front 39

What determines the strength of the force of gravity between two objects?

Back 39

The masses of the objects and the distance between them.

Front 40

What two factors combine to keep the moon and Earth in orbit?

Back 40

inertia and gravity

Front 41

force

Back 41

A push or a pull exerted on an object.

Front 42

gravity

Back 42

The attractive force between objects; its strength depends on their masses and the distance between them.

Front 43

law of universal gravitation

Back 43

The scientific law that states that every object in the universe attracts every other object.

Front 44

mass

Back 44

The amount of matter in an object.

Front 45

weight

Back 45

The force of gravity on an object.

Front 46

inertia

Back 46

The tendency of an object to resist a change in motion.

Front 47

Newton’s first law of motion

Back 47

The scientific law that states that an object at rest will stay at rest and an object in motion will stay in motion with a constant speed and direction unless acted on by a force.

Front 48

What causes the phases of the moon?

Back 48

The changing relative positions of the moon, Earth, and sun.

Front 49

What are solar and lunar eclipses?

Back 49

A solar eclipse occurs when the moon passes directly between Earth and the sun, blocking sunlight from Earth. During a lunar eclipse, Earth blocks sunlight from reaching the moon.

Front 50

What causes the tides?

Back 50

Tides are caused mainly by differences in how much the moon’s gravity pulls on different parts of Earth.

Front 51

phases

Back 51

One of the different apparent shapes of the moon as seen from Earth.

Front 52

eclipse

Back 52

The partial or total blocking of one object in space by another.

Front 53

umbra

Back 53

The darkest part of a shadow.

Front 54

penumbra

Back 54

The part of a shadow surrounding the darkest part.

Front 55

tide

Back 55

The periodic rise and fall of the level of water in the ocean.

Front 56

spring tide

Back 56

The tide with the greatest difference between consecutive low and high tides.

Front 57

neap tide

Back 57

The tide with the least difference between consecutive low and high tides.

Front 58

What features are found on the moon’s surface?

Back 58

maria, craters, and highlands

Front 59

What are some characteristics of the moon?

Back 59

The moon is dry and airless. Compared to Earth, the moon is small and has large variations in its surface temperature.

Front 60

How did the moon form?

Back 60

Scientists theorize that a planet-sized object collided with Earth to form the moon. Material from the object and Earth’s outer layers was ejected into orbit around Earth, where it formed a ring. Gravity caused this material to combine to form the moon.

Front 61

telescope

Back 61

A device built to observe distant objects by making them appear closer.

Front 62

maria

Back 62

Dark, flat areas on the moon’s surface formed from huge ancient lava flows.

Front 63

craters

Back 63

A large round pit caused by the impact of a meteoroid.

Front 64

meteoroids

Back 64

A chunk of rock or dust in space.

Front 65

What is the main advantage of a multistage rocket?

Back 65

The main advantage of a multistage rocket is that the total weight of the rocket is greatly reduced as the rocket rises.

Front 66

thrust

Back 66

The reaction force that propels a rocket forward.

Front 67

Newton's 3rd law of motion

Back 67

For every force, or action, there is an equal and opposite force, or reaction

Front 68

What are the geocentric and heliocentric systems?

Back 68

In a geocentric system, Earth is at the center of the revolving planets and stars. In a heliocentric system, Earth and the other planets revolve around the sun.

Front 69

What objects make up the solar system?

Back 69

the sun, the planets and their moons, dwarf planets, asteroids, and comets

Front 70

ellipse

Back 70

An oval shape, which may be elongated or nearly circular; the shape of the planets’ orbits.

Front 71

What are the three layers of the sun’s interior?

Back 71

the core, the radiation zone, and the convection zone

Front 72

What are the three layers of the sun’s atmosphere?

Back 72

the photosphere, the chromosphere, and the corona

Front 73

What features form on or above the sun’s surface?

Back 73

sunspots, prominences, and solar flares

Front 74

core

Back 74

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

Front 75

radiation zone

Back 75

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

Front 76

convection zone

Back 76

The outermost layer of the sun’s interior.

Front 77

photosphere

Back 77

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

Front 78

chromosphere

Back 78

The middle layer of the sun’s atmosphere. The reddish glow visible during a total solar eclipse.

Front 79

corona

Back 79

The outer layer of the sun’s atmosphere that extends into space for millions of kilometers.

Front 80

solar wind

Back 80

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

Front 81

sunspot

Back 81

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

Front 82

prominence

Back 82

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

Front 83

solar flare

Back 83

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

Front 84

What characteristics do the inner planets have in common?

Back 84

The four inner planets are small and dense and have rocky surfaces.

Front 85

What are the main characteristics that distinguish each of the inner planets?

Back 85

Earth is unique in our solar system in having liquid water at its surface. Mercury is the smallest terrestrial planet and the planet closest to the sun. Venus rotates from east to west, the opposite direction from most other planets and moons. Mars is called the “red planet,” because of its reddish rocks.

Front 86

terrestrial planets

Back 86

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

Front 87

greenhouse effect

Back 87

The trapping of heat by a planet’s atmosphere.

Front 88

What characteristics do the gas giants have in common?

Back 88

much larger and more massive than Earth, and they do not have solid surfaces. They all have rings.

Front 89

What characteristics distinguish each of the outer planets?

Back 89

Jupiter is the largest and most massive planet. Saturn has the most spectacular rings of any planet. Uranus’s axis of rotation is tilted at an angle of about 90 degrees from the vertical. Neptune is a cold, blue planet. Its atmosphere contains visible clouds.

Front 90

ring

Back 90

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

Front 91

What are the characteristics of comets?

Back 91

Comets are loose collections of ice, dust, and small rocky particles whose orbits are usually very long, narrow ellipses.

Front 92

Where are most asteroids found?

Back 92

Most asteroids revolve around the sun between the orbits of Mars and Jupiter.

Front 93

Kuiper Belt

Back 93

A doughnut-shaped region that stretches from around Pluto’s orbit to about 100 times Earth’s distance from the sun.

Front 94

asteroid

Back 94

Rocky objects revolving around the sun that are too small and numerous to be considered planets.

Front 95

What is the difference among meteoroid, meteor, and meteorite?

Back 95

A meteoroid is a chunk of rock or dust in space. A meteor is a streak of light in the sky produced by the burning of a meteoroid in Earth’s atmosphere. A meteorite is a meteoroid that passes through the atmosphere and hits Earth’s surface.

Front 96

What is the big bang theory?

Back 96

According to the big bang theory, the universe formed in an instant, 13.7 billion years ago.

Front 97

What is the evidence for the big bang theory?

Back 97

Cosmic background radiation and galaxies moving apart.

Front 98

How did the solar system form?

Back 98

4.5 billion years ago, a giant cloud of gas and dust collapsed to form our solar system. Nuclear fusion began at the center forming the sun. Clumps of rock and dust, called planetesimals, joined together to form planets.

Front 99

Is our universe expanding?

Back 99

Yes

Front 100

solar nebula

Back 100

A large cloud of gas and dust, such as the one that formed our solar system.

Front 101

planetesimals

Back 101

One of the small asteroid-like bodies that formed the building blocks of the planets.

Front 102

What is dark matter?

Back 102

Matter that does not give off electromagnetic radiation but is quite abundant in the universe.

Front 103

What is dark energy?

Back 103

A mysterious force that appears to be causing the expansion of the universe to accelerate.