Astro Final

Front 1

Absolute visual magnitude is

Back 1

the apparent magnitude of a star observed from a distance of 10 pc.

Front 2

____ are star-like objects that contain less than .08 solar masses an will never raise their core temperatures high enough that the proton-proton chain can begin. Other minor fusion reactions do occur in these objects. They fall in a gap between the low-mass M dwarf stars and the massive planets in which nuclear fusion never occurs.

Back 2

brown dwarf

Front 3

Most of the visible light we see coming from the sun originates from the

Back 3

photosphere

Front 4

Which of the following is evidence of an impact crater?

Back 4

overturned rocks, fluffy carbon, shocked quartz are possible

Front 5

Each element has its own set of characteristic absorption lines because

Back 5

electron energy levels differ for each element.

Front 6

The sunspot activity of the sun is cyclic, and shows periods of high sunspot activity approximately every

Back 6

11 years

Front 7

The absorption lines of a star are determined to be blue shifted, this means that they show a

Back 7

higher frequency and the star is moving toward us

Front 8

One hypothesis suggested to explain the uniform age of the surface of Venus is that

Back 8

Venus periodically goes through a catastrophic melting of the entire surface

Front 9

What characteristic of a star primarily determines its location on the main sequence?

Back 9

mass

Front 10

Comet Shoemaker-Levy 9 broke apart before impacting which body in our solar system? We were able to “see” the impact happen with spacecraft in the area.

Back 10

Jupiter

Front 11

The neutral hydrogen atom consists of

Back 11

one proton and one electron

Front 12

The diagram illustrates a light source, a gas cloud, and three different lines of sight. Along which line of sight would an observer see a continuous spectrum?

Back 12

1(the line directly pointing to the light bulb)

Front 13

The diagram illustrates a light source, a gas cloud, and three different lines of sight. Along which line of sight would an observer see an absorption spectrum?

Back 13

3(through the gas lamp and reaches to the bulb)

Front 14

The diagram illustrates a light source, a gas cloud, and three different lines of sight. Along which line of sight would an observer see an emission spectrum?

Back 14

2(through the gas cloud but doesn't make it to the bulb)

Front 15

The hydrogen in our solar system was created from subatomic particles in

Back 15

The Big Bang

Front 16

This part of a comet is very straight, and pointed directly away from the sun (due to the solar wind)

Back 16

ion tail

Front 17

The lowest energy level in an atom is

Back 17

the ground state

Front 18

What force(s) are responsible for the collapse of an interstellar cloud?

Back 18

gravity

Front 19

Interstellar gas clouds may collapse to form stars if they

Back 19

encounter a shock wave

Front 20

A ____ is a meteor which explodes before reaching the ground, although some fragments will hit the ground.

Back 20

bolide

Front 21

The sun has a surface temp. of approximately 5800 K. At what wavelength does the maximum energy radiated by the sun?

Back 21

520nm

Front 22

One star has a temperature of 10,000 K and another star has a temperature of 5,000 K. Compared to the cooler star, how much more energy per second will the hotter star radiate from each square meter of its surface?

Back 22

16 times

Front 23

A(n) ___ is a solar system object that enters Earth’s atmosphere and becomes very hot as it passes through the earth's atmosphere and does not survive to reach the surface.

Back 23

meteor

Front 24

In the diagram, which of the transitions would require the electron to absorb a photon with greatest energy (shortest wavelength)?

Back 24

Transition 4 (starts at nucleus and stops at 5th level)

Front 25

If the transition 3 is known to occur with an ultraviolet photon, then what kind of photon causes transition 4 to occur?

Back 25

ultraviolet photon

Front 26

A short period comet typically has a period of ____ and originated in the Kuiper belt.

Back 26

less than 200 years

Front 27

The brightness curve of binary stars helps us determine the period and the mass of those stars. Which type would a brightness curve help the most?

Back 27

eclipsing

Front 28

For observations of parallax angles of stars as seen from Earth, the baseline for

Back 28

2AU

Front 29

When geologists look at exposed rock layers around the world, they find evidence of the catastrophic event which probably caused the extinction of the dinosaurs. The period before the event is called the Cretaceous and the period after is called the Tertiary. The rock layer at the boundary between the two is about 65 million years old and is enriched in the element iridium. The name for this layer is called the

Back 29

K-T boundary

Front 30

Sunspots

Back 30

are cooler than their surroundings

Front 31

The sun’s magnetic field changes polarity every ___, so that the true solar magnetic cycle is ___.

Back 31

11 years, 22 years

Front 32

Protostars are difficult to observe because

Back 32

the protostar stage is very short, they are surrounded by cocoons of gas and dust, they radiate mainly infrared.

Front 33

The radiation emitted from a star has a maximum intensity at a wavelength of 300 nm. What is the likely temperature of this star?

Back 33

10,000 K

Front 34

Star A has m=2, and star B has m=7. Which star could be seen on a clear night in Santa Barbara without a telescope or binoculars?

Back 34

Star A only

Front 35

A 100W bulb, 2 meters from you is the same brightness as a ___ bulb held 1m away.

Back 35

25

Front 36

The solar wind from our star is made up of

Back 36

hydrogen nuclei, helium nuclei, electrons

Front 37

The head of a comet is comprised of the

Back 37

Nucleus and coma

Front 38

Stars on the main sequence with the greatest mass

Back 38

are spectral type O stars

Front 39

The temperature of an object from which no heat energy can be extracted is

Back 39

0 K

Front 40

The two most abundant elements in the sun are

Back 40

hydrogen and helium

Front 41

Red giant stars are

Back 41

more luminous than the sun, larger in diameter than the sun, cooler than B stars, located above the main sequence stars in the H-R diagram.

Front 42

___ pushes gas and dust particles out of the solar nebula by the light from the sun.

Back 42

Radiation pressure

Front 43

A star which is half the mass of our sun is on the main sequence of an H-R diagram. Which of the following spectral classes would you expect it to be?

Back 43

K

Front 44

As a star begin to form the initial energy source that causes them to glow is from

Back 44

gravitational potential energy

Front 45

We know that giant stars are larger in diameter than the sun because

Back 45

they are more luminous but have about the same temperature

Front 46

Where on the above H-R diagram would you find a red dwarf?

Back 46

3 (highest in temp, and .1 in luminosity)

Front 47

Where on the H-R diagram would you find a white dwarf?

Back 47

1 (temperature 15,000, .01 in luminosity)

Front 48

A plot of the continuous spectra of five different stars is shown in the figure. Based on these spectra, which of the stars is the hottest?

Back 48

Star A (has the biggest curve)

Front 49

The coma of a comet is

Back 49

is formed be solid volatile ices sublimating into gases and a gas cloud around the comet nucleus

Front 50

If you compare two stars,

Back 50

the one with the lower absolute magnitude will always have the greater luminosity

Front 51

While on the main sequence a star’s primary energy source comes from

Back 51

nuclear fusion

Front 52

A long period comet can have an orbital period of 1 million years. Long period comets originate from the

Back 52

Oort cloud

Front 53

Emission nebulae are also called ___ because they are composed of ionized hydrogen.

Back 53

HII regions

Front 54

The lowest mass object that can initiate thermonuclear fusion of hydrogen has a mass of about

Back 54

.08 solar masses

Front 55

If two stars are emitting the same amount of light, the star that is further will appear

Back 55

dimmer

Front 56

The hydrogen lines in spectral type A stars

Back 56

are most narrow for supergiants

Front 57

Fluffy carbon is mostly made of

Back 57

carbon nanotubes

Front 58

An atom that is excited

Back 58

can emit a photon when the electron moves to a lower energy

Front 59

The sun’s magnetic field is evident in the looped shapes of

Back 59

prominences

Front 60

What observation made of other stars seems to suggest the solar nebula hypothesis is correct?

Back 60

Young stars are found to have hot disks that surround them

Front 61

Differential rotation of the sun

Back 61

the equatorial regions of the sun rotating more rapidly than the polar regions

Front 62

You are standing near a railroad track and a train is moving toward you at 60 mph and blowing its horn. What will you notice as the train moves past you?

Back 62

As the train approaches, the horn will sound higher in pitch than when the train is moving away.`

Front 63

Parallax would be easier to measure if

Back 63

Earth’s orbit was longer.

Front 64

Due to the dust in the interstellar medium, a distant star will appear to an observer on Earth to be

Back 64

fainter and cooler than it really is

Front 65

In the H-R diagram, 90 percent of all stars are

Back 65

on the main sequence

Front 66

The tail of a comet points

Back 66

away from the sun

Front 67

From the data given, which star in the table has the greatest luminosity?

Back 67

58 Ori(least amount in the Mv){-6.0}

Front 68

From the data given, which star in the table would appear the faintest in the night sky?

Back 68

65 Tau (greatest mv) (4.2)

Front 69

From the data given, which star in the table has the greatest surface temperature?

Back 69

HR 4621 (spectral type B)

Front 70

Star A has m=3, and star B has m=8. Which star is brighter and how much brighter is it?

Back 70

Star A, 100X

Front 71

The youngest part of Earth’s crust are

Back 71

the midocean rifts

Front 72

There is a main sequence mass-luminosity relation because

Back 72

more massive stars support their large weight by making more energy

Front 73

The most common stars are

Back 73

lower mass (less luminous) main sequence stars.

Front 74

The iron in our solar system was created from smaller mass atomic nuclei in

Back 74

supernovas

Front 75

Condensation in the solar nebula probably led to the formation of icy grains beyond the present orbit of jupiter

Back 75

metallic grains near the present orbit of mercury and silicate grains near the present orbit of

Front 76

____ occurs when light travels out of a gravitational field, loses energy and its wavelength grows longer.

Back 76

a gravitational red shift

Front 77

Younger stars have more heavy elements because

Back 77

the heavy elements were made in previous generations of stars.

Front 78

Population II stars

Back 78

are primarily old low mass stars, and are located in globular clusters.

Front 79

How is the age of the galaxy determined?

Back 79

Finding the turnoff point in the H-R diagram of globular clusters.

Front 80

Which of the following can be used as distance indicators for galaxies (to figure out how far away galaxies are)?

Back 80

Only Cepheid Variables and Supernova Type I

Front 81

According to Hubble's Law, if Galaxy A is found to have a recessional velocity four times greater than Galaxy B, what can you say about their relative distance from Earth?

Back 81

Galaxy A is four times further away from Galaxy B

Front 82

A nova is almost always associated with

Back 82

a white dwarf in a close binary system.

Front 83

The H-R diagram of a young star cluster shows

Back 83

that low mass stars have not yet reached the main sequence yet.

Front 84

A white dwarf is composed of

Back 84

carbon and oxygen nuclei and degenerate electrons.

Front 85

What are the two longest stages in life of a one solar mass star?

Back 85

Main-sequence, white dwarf.

Front 86

Stars with masses between 0.4 Mo and 4 Mo

Back 86

undergo thermonuclear fusion of hydrogen and helium, but never get hot enough to ignite carbon.

Front 87

About how old is the earth compared to the age of the universe?

Back 87

about 1/3 as old

Front 88

A satellite is originally orbiting the Earth at a distance of 10,000 km from the center of the Earth. When the satellite moves to a new orbital distance of 20,000 km from the center of the Earth, how will the gravitational force change?

Back 88

the force of gravity will be 1/4 as large

Front 89

If you lived at the South Pole, when would it be daytime, and how long would the day last?HINT: Think about how the Earth is tilted (toward the sun or away from the sun).

Back 89

6-month day, from September to March

Front 90

Newton concluded that a force from the Earth had to act on the moon because

Back 90

a force is needed to accelerate the moon toward Earth away from straight-line motion.

Front 91

Retrograde motion, where a planet normally travels in one direction (prograde), then reverses for only a short period of time,

Back 91

is observable for all planets.

Front 92

Saturn's orbital distance is about 10 AU from the sun. What is the approximate orbital period of Saturn? Recall that Kepler's 3rd law is P2 = d3.

Back 92

32 years

Front 93

The eccentricity of a planet's orbit describes

Back 93

the deviation in shape when compared to a circle.

Front 94

The Milky Way Galaxy

Back 94

contains more than 200 billion stars.

Front 95

The __________ moon is visible on the western horizon a couple of hours before sunrise.

Back 95

waxing gibbous

Front 96

What conditions contribute to a long solar eclipse, such as the total solar eclipse of July 11, 1991 - one of the longest on record? (**Hint the recent Supermoon meant that the moon was at perigee**)

Back 96

in their elliptical orbits, the Moon is at perigee while Earth is at aphelion

Front 97

The large planetesimals would have grown faster than the smaller planetesimals because

Back 97

their stronger gravity would pull in more material

Front 98

Auroras around a body indicate that the body has

Back 98

magnetic field

Front 99

Which of the following objects is found in the Kuiper belt

Back 99

eris

Front 100

Protoplanets grew in size by

Back 100

collision and coalescence of planetesimal

Front 101

____ do not contain liquid metallic hydrogen because they are not massive enough.

Back 101

Uranus and Neptune

Front 102

Uranus's interior

Back 102

Doesn't contain any liquid metallic hydrogen because the pressure is so low. Has a small core of heavy elements(in the form of ice).

Front 103

The central regions of earth's core are solid because

Back 103

the pressure at the center raises the melting points

Front 104

This planet has the most extreme seasons of the planets in our solar system

Back 104

Uranus

Front 105

The ____ keeps venus hot because the atmosphere is predominantly carbon dioxide

Back 105

greenhouse effect

Front 106

The satellites discovered by galileo orbit the planet

Back 106

Jupiter

Front 107

The flow patterns found on the surface of mars and the number of craters on top of them suggest that the climate on mars was

Back 107

different billions of years ago

Front 108

The moons are mars are

Back 108

deimos and phobos

Front 109

The greenhouse effect occurs on earth because

Back 109

carbon dioxide is transparent to visible light and opaque to infrared radiation

Front 110

_____ pushed gas and dust particles out of the solar nebula by the light from the sun.

Back 110

Radiation pressure

Front 111

Europa has few craters because

Back 111

it has erased craters nearly as fast as they have forme

Front 112

Saturn's rings are

Back 112

in the plane of the planet's equator, composed of ice particles, inside the Roche limit

Front 113

_____ is an object what is most like the planetesimals that formed in the solar nebula.

Back 113

Asteroids

Front 114

Before the kepler mission, most of the bodies that were discovered from radial velocity consisted of very massive bodies which orbit close to their star. These planets are known

Back 114

hot Jupiters.

Front 115

____ is a satellite of pluto.

Back 115

Charon

Front 116

The old surfaces of icy satellites of jovian planets

Back 116

appear dark in color with many impact craters.

Front 117

A(n) _____ is a planet found orbiting around a star other than the sun.

Back 117

extrasolar planet

Front 118

____ does not have crustal plates on its surface.

Back 118

Jupiter

Front 119

The first solid grains of ____ formed in hot regions near the sun. Much farther from the sun the first grains (or rather flakes) of water ice also formed by a similar process as the close-in grains, condensation.

Back 119

iron

Front 120

Newton concluded that a force from the earth had to act on the moon because

Back 120

.. a force is needed to accelerate the moon toward earth away from straight-line motion.

Front 121

In terms of mass, Jupiter is made mostly of

Back 121

hydrogen and helium.

Front 122

Acceleration among the grains in the solar nebula would have been aided by

Back 122

static electricity.

Front 123

Why is it believed that the rings of Saturn could not have formed just as the planet itself formed?

Back 123

the rings are made of ice particles which would have been vaporized by the heat released as Saturn formed.

Front 124

Why did mars lose its atmosphere?

Back 124

the lack of magnetic field.. solar wind blew it away.. weaker gravitational force.

Front 125

After the first solid grains formed in our solar system, these particles could then grow by the process of ____. The collision and sticking of one particle with another to continue the formation of ______. Each of these has many atoms or molecule

Back 125

accretion, planetesimals

Front 126

_______ supports the idea that the martian crust is not divided into moving plates like those on earth.

Back 126

The size of Olympus mons, the lack of folded mountain chains, the lack of rift valleys outlining entire plates

Front 127

The _____ moon is visible on the western horizon a couple hours before sunrise.

Back 127

waxing gibbous

Front 128

Moon is no longer geologically active because

Back 128

it is much smaller in mass.

Front 129

The protective magnetic field of the earth is generated in this layer

Back 129

Solid metal core

Front 130

This moon of Saturn is nicknamed the death star because of its giant crater

Back 130

mimas

Front 131

The eccentricity of a planet's orbit describes the deviation in shape when compared to a

Back 131

circle.

Front 132

The planets all lie in nearly the same plane resulting in a disk-like structure for the solar system. This disk-like structure is believed

Back 132

to exist because the solar nebula from which the planets formed had a disk like structure.

Front 133

This nasa mission recently did a flyby of the dwarf planet pluto and took photos as well as a whole host of other data.

Back 133

Rosetta

Front 134

The kepler satellite mission uses which planet detecting technique?

Back 134

transit method

Front 135

Mercury has a surface which is older than venus.

T or F

Back 135

T

Front 136

If you lived at the south pole….. when would it be daytime, and how long?

Back 136

6-month day, from September to December

Front 137

In contrast to the outer solid mantle, parts of the central region of earth's interior are thought to be fluid because______ cannot make it through those regions.

Back 137

S seismic waves

Front 138

_____ is the most geologically active of the Galilean satellites.

Back 138

Io

Front 139

_____ does not have a crustal plates on its surface.

Back 139

Jupiter

Front 140

Why is Saturn moon Titan able to retain an atmosphere?

Back 140

it has a large enough mass and is cold enough

Front 141

Why is saturn oblate?

Back 141

the rapid rotation of the planet flattens it

Front 142

Geology of venus appears to be dominated by

Back 142

volcanism

Front 143

One hypothesis suggested to explain the uniform age of the surface of venus

Back 143

venus periodically goes through a catastrophic melting of the entire surface.

Front 144

What type of geological activity is seen on Neptune’s moon triton?

Back 144

Geysers of liquid nitrogen are seen erupting from its surface

Front 145

Milky way galaxy contains _____ stars.

Back 145

more than 200 billion

Front 146

Belt and zone circulation

Back 146

occurs on Jupiter, occurs on Saturn, is caused by rising and sinking gases, is more obvious on Jupiter than on Saturn. The answer is all of the above.

Front 147

Both Jupiter and Saturn

Back 147

all of the above: have liquid metallic hydrogen in their interiors, emit more energy than they absorb from the sun, have belt and zone circulation, have rings

Front 148

Mars has a sufficient mass and a low enough temperature that water molecules could exist in its atmosphere as vapor. One reason mar’s atmosphere does not contain a significant amount of water vapor is that

Back 148

ultraviolet radiation breaks the water molecule into less massive particles that can escape

Front 149

Tycho Brahe's greatest contribution to astronomy was his

Back 149

discovery of three laws of motion

Front 150

Neap tides occur

Back 150

when the moon is first or third quarter

Front 151

The Copernican system was no more accurate than the Ptolemaic system in predicting the positions of the planets because

Back 151

the Copernican system used uniform circular motion.

Front 152

The _____ moon is visible near the eastern horizon a couple hours before sunrise

Back 152

waning crescent

Front 153

An epicycle is

Back 153

a small circle whose center is located on the circumference of another larger circle.

Front 154

What is the ratio of the light gathering power of a 3m telescope to that of a 1m telescope?

Back 154

9 to 1

Front 155

which day of the week is associated with the planet mars?

Back 155

Tuesday

Front 156

In which position is the northern hemisphere experiencing the autumnal equinox?

Back 156

b

Front 157

Why did galileo's observations of moons orbiting Jupiter disagree with geocentric model of the universe of the moons?

Back 157

did not appear to orbit the earth

Front 158

Newton's third law

Back 158

you cannot move yourself. As you walk along the ground, your feet push back on the ground and the ground in turn pushes you forward. the size of the force you feel is the same as the force you push against the ground, but the direction is the opposite.

Front 159

Gamma rays, ultraviolet light, and x-rays have wavelengths that are

Back 159

shorter than visible light.

Front 160

Tycho did not accept a _____ of the universe.

Back 160

heliocentric model

Front 161

First quarter moon rises at

Back 161

noon.

Front 162

x-ray telescopes must be used

Back 162

above earth's atmosphere

Front 163

synodic period is

Back 163

29.5 day long, which is the period of time for the moon to complete a cycle of the lunar phases

Front 164

______ of mars can best be explained as earth overtaking and passing mars.

Back 164

retrograde motion

Front 165

Ultraviolet radiation is absorbed by ozone in earth's atmosphere that is located between 20km and 40 km above earth's surface. Therefore, telescopes to observe this radiation must be placed

Back 165

in space.

Front 166

light gathering power

Back 166

biggest diameter and biggest focal length

Front 167

kepler's 3rd law of planetary motion

Back 167

the larger the orbit, the longer its orbital period

Front 168

Chromatic aberrations occurs

Back 168

in a refracting telescope when different colors of light do not focus at the same point

Front 169

in a reflecting telescope the objective is

Back 169

a mirror

Front 170

spring tides occur at

Back 170

new moon and full moon

Front 171

The very long baseline interferometer is

Back 171

a set of radio telescopes linked together electronically to provide very high resolution

Front 172

total lunar eclipses always occur at at the time of

Back 172

a full moon

Front 173

the sun is

Back 173

visible by its own light emissions 1 au from earth and a star which generates its own energy

Front 174

The sidereal period of the moon is

Back 174

all of the above.. 27.32, and is the period of time for the moon to orbit earth once with respect to the stars

Front 175

A new generation of ground based telescopes is currently being built that overcomes the limitations of the older large telescopes. Some of these new telescopes.

Back 175

Use active optics to control the shape of the mirror. Use segmented mirrors and use mirrors that are very thin

Front 176

A telescope whose objective is a lens and contains no mirrors is a

Back 176

refracting telescopes

Front 177

A solar or lunar eclipse will occur when

Back 177

the sun is near the line of nodes of the moon and the moon is new or full.

Front 178

Galileo’s observations of a complete set of phases of Venus proved that

Back 178

Venus orbited the sun

Front 179

The energy of a photon is directly proportional to the

Back 179

frequency

Front 180

following distances in order from SMALLEST TO LARGEST. (AU, yard, LY, kilometer)

Back 180

yard, kilometer, AU, LY

Front 181

What is the longest wavelength of light that can be seen with the human eye?

Back 181

700 nm

Front 182

Precession of the rotation axis is caused by?

Back 182

the torque of gravity from the sun and moon on earth's equatorial bulge

Front 183

Infrared radiation is absorbed by water in earth's atmosphere and requires that telescopes for observing at these wavelengths be placed

Back 183

on mountains tops or in space

Front 184

A satellite is originally orbiting the earth at a distance of 10,000 km from the center of the earth. When the satellite moves to a new orbital distance of 20,000 km from the center of the earth, how will the gravitational force change?

Back 184

the force of gravity will be ¼ as large

Front 185

Kepler's second law

Back 185

implies that a planet should move at its greatest speed when it is closest to the sun

Front 186

A comet is found in a highly elliptical orbit to have a semi-major axis (like orbital radius) equal to one AU. According to kepler's 3rd law what would be the sidereal period of this comet

Back 186

it will be one year

Front 187

Radio telescopes are important in astronomy because

Back 187

they can detect cool hydrogen

Front 188

Retrograde motion is observable from

Back 188

all planets

Front 189

According to Newtonian mechanics, a force must be acting on a body if the body changes its

Back 189

velocity

Front 190

How is a planet different than a star?

Back 190

Planets reflect light while stars produce their own light

Front 191

During the month of June, the north axis of earth points towards Polaris but during the month of December it points

Back 191

still towards Polaris

Front 192

Kepler's first law of planetary motion

Back 192

implies that the planets move in elliptical orbits around the sun

Front 193

Darkest part of the earth's shadow is

Back 193

the umbra

Front 194

the diameter of the earth is approx.

Back 194

12800 km

Front 195

A total solar eclipse always occur at which phase of the moon?

Back 195

New moon

Front 196

parallax is

Back 196

the apparent motion of an object due to the motion of the observer

Front 197

The mass of an object is a measure of the amount of matter it contains, on the other hand, weight is

Back 197

a measure of the gravitational force on an object

Front 198

the orbit of the planet Saturn is an ellipse with the sun at one focus. What is locate at the other focus?

Back 198

nothing

Front 199

an observer in the northern hemisphere watches the sky for several hours. Due to the motion of earth, this observer notices that the stars near the north celestial pole appear to move ____ around the celestial pole.

Back 199

counterclockwise

Front 200

Gamma rays is

Back 200

a type of electromagnetic radiation that has the greatest energy.

Front 201

photons of ___ light have a greater energy than photons of ____ light

Back 201

blue, green

Front 202

Luminosity is dependent on

Back 202

the size of the star, give more light in total but be as cool.

Front 203

Two light bulbs are the same but if you made one a lot bigger,

Back 203

the brightness doesn’t change but the bigger one is luminous because it is bigger in radius

Front 204

A nova

Back 204

(a sudden and temporary brightening of a star making it appear as a new star in the sky, evidently caused by an explosion of nuclear fuel on the surface of a white dwarf)

Front 205

The theory that Mercury shrank slightly when it was young has been proposed to explain

Back 205

lobate scarps

Front 206

The greenhouse effect keeps Venus hot because

Back 206

the atmosphere is predominantly carbon dioxide

Front 207

Coronae on Venus are believed to be

Back 207

caused by rising convection currents in the interior of Venus.

Front 208

Mars has a sufficient mass and a low temperature that water molecules could exist in its atmosphere as vapor. One reason Mar's atmosphere does not contain a significant amount of water vapor is that

Back 208

Ultraviolet radiation breaks the water molecule into less massive particles that can escape.

Front 209

The extreme size of volcanoes on Mars indicate that

Back 209

Mars has a much thicker crust on Earth and large moving plates have not formed on Mars.

Front 210

The Roche Limit is the

Back 210

distance from a planet within which a satellite cannot hold itself together.

Front 211

Planets were first detected around distant stars by the Doppler effect. The Doppler effect causes light from a body moving toward us to be shifted to... (frequency: longer, lower, higher)

Back 211

higher frequency

Front 212

If light takes 8 minutes to travel from the sun to Earth and over 4 hours to travel from the sun to the planet Neptune, what is the distance from the sun to Neptune?

Back 212

30 AU

Front 213

If the distance to the nearest star is 4.2 light-years, then

Back 213

the light we see left the star 4.2 years ago.

Front 214

The radius of the moon's orbit is about ____ times larger than the radius of Earth.

Back 214

60

Front 215

A total lunar eclipse is

Back 215

visible to all observers on the side of Earth from which the moon would be visible at that time.

Front 216

An observer in the Northern Hemisphere watches the sky for several hours. Due to the motion of Earth, this observer notices that the stars near the north celestial pole appear to move

Back 216

counter clockwise around the celestial pole.

Front 217

Seen from the northern latitudes (mid-northern hemisphere), the star Polaris

Back 217

is always above the northern horizon.

Front 218

The apparent visual magnitude of a star is a measure of the star's

Back 218

intensity.

Front 219

The lowest amount of solar energy per square meter is incident upon the surface of Earth in the northern hemisphere on or about

Back 219

December 21, the winter solstice.

Front 220

The moon has an angular diameter of 0.5°. What is the moon's angular diameter in minutes of arc?

Back 220

30

Front 221

The point in Earth's orbit where Earth is farthest from the sun is known as

Back 221

aphelion.

Front 222

The saros cycle

Back 222

all of the above

-was used in ancient times to predict eclipses.

-is 18 years, 11 1/3 days long.

-comes from a Greek word that means repetition.

Front 223

The __________ moon is visible on the western horizon a couple of hours after sunrise.

Back 223

waning gibbous

Front 224

When will the full moon be highest above the southern horizon for an observer in the Northern Hemisphere? **Hint: the full moon is always "opposite the sun" when seen from the Earth.

Back 224

at midnight near the winter solstice

Front 225

Which of the following historical characters developed a mathematically based geocentric theory of the earth at the center of the cosmos?

Back 225

Ptolemy

Front 226

As a bird flies, its wings push air downwards. At the same time, the air also pushes the bird upwards. The size of the force on the air equals the size of the force on the bird, and the direction of the force on the air (downwards) is opposite the direction of the force on the bird (upwards). This is an example of which of Newton's three laws of motion?

Back 226

Newton's third law

Front 227

Which of the following historical characters was first to propose that the sun was at the center of the cosmos?

Back 227

Nicolaus Copernicus

Front 228

Galileo Galilei

Back 228

All of the above

greatly improved the design of the telescope.

-observed the phases of Venus.

-observed the moons of Jupiter.

-discovered sunspots.

Front 229

Newtons law of universal gravitation states that any two bodies in the universe attract each other with a force that is __________ proportional to the product of their masses and __________ proportional to the square of the distance between them.

Back 229

directly; inversely

Front 230

Tycho Brahe's greatest contribution to astronomy was

Back 230

his 20 years of careful observations of the planets.

Front 231

Ptolemys model of the universe

Back 231

contained epicycles.

Front 232

If a planet were orbiting the Sun in an orbit three times as far as its current orbit, how many times longer would it take the planet to go around the sun, as compared to its current rate of revolution?

Back 232

About 5.2

Front 233

Ptolemy's purpose in using epicycles to explain the motion of the planets in the night sky was to account for

Back 233

retrograde motion.

Front 234

Which of Kepler’s laws of planetary motion states that the orbit of every planet is an ellipse with the sun at one of the two foci?

Back 234

Kepler's first law

Front 235

A ____ has a few million light sensitive diodes in an array typically about a half-inch square.

Back 235

charge-coupled device

Front 236

Astronomers build telescopes on tops of mountains because

Back 236

there is less air to dim the light and the seeing is better.

Front 237

Chromatic aberration occurs in a ____ telescope when ____.

Back 237

refracting; different colors of light do not focus at the same point.

Front 238

In which way does a photon of blue light NOT differ from a photon of red light?

Back 238

speed

Front 239

The energy of a photon

Back 239

is inversely proportional to the wavelength of the light.

is directly proportional to the frequency of the light

Front 240

The technique of connecting multiple telescopes together to combine the images from each telescope is known as

Back 240

interferometry.

Front 241

What is the ratio of the light gathering power of a 10 m telescope to that of a 1 m telescope?

Back 241

100 to 1

Front 242

____ is absorbed by water in Earth's atmosphere and requires that telescopes for observing at these wavelengths be placed on mountain tops or in space.

Back 242

Infrared radiation

Front 243

How rapidly a planet loses its atmosphere depends on the planet's

Back 243

temperature, atmospheric composition, escape velocity (determined by mass and radius)

Front 244

In the development of a terrestrial planet, the stage of ____ when dense material settled to the core and less dense to the outer parts.

Back 244

differentiation

Front 245

Motion of the plates of Earth's crust is thought to be due to

Back 245

convection from the hot interior.

Front 246

That the moon has no magnetic field implies that

Back 246

the moon's core contains little if any molten iron.

Front 247

The greenhouse effect produces excess heat in a planet's atmosphere by

Back 247

trapping infrared radiation from escaping into space.

Front 248

The Himalayan Mountains are rugged, jagged peaks and the Appalachians are smooth and rolling. Why is there a difference?

Back 248

The Appalachians are much older and have been smoothed by erosion.

Front 249

The lunar maria are

Back 249

the lava plains of the lunar lowlands.

Front 250

What do astronomers generally believe about the origin of Mars' moons?

Back 250

They formed elsewhere and were captured at a later time.

Front 251

Which hypothesis concerning the formation of the Moon makes predictions that best fit the observed lunar data?

Back 251

The large impact hypothesis

Front 252

Which of the terrestrial planets has the most difficult time retaining an atmosphere?

Back 252

Mercury

Front 253

Why does Mars have seasons similar to the Earth?

Back 253

Mars' rotational axis is tilted relative to its orbit like the Earth's.

Front 254

____ is a very long and deep canyon on Mars.

Back 254

Valles Marineris

Front 255

At Jupiter's very center is probably a small core of

Back 255

heavy element (molten rock and iron) core

Front 256

Some narrow rings of Saturn are seen in space probe photos to be caused by

Back 256

small shepherd moons that orbit inside and outside the rings

Front 257

The magnetic fields of Uranus and Neptune are peculiar in that they are

Back 257

highly inclined to their planet's axis of rotation.

Front 258

The reddish particles in Jupiter's ring are less than 1 percent as reflective as Saturn's whiter particles. Saturn's ring particles are thought to be ____while Jupiters are thought to be ______

Back 258

icy; rocky

Front 259

The ____ of a planet is the region around the planet where the magnetic field is able to deflect the solar wind and other charged particles.

Back 259

magnetosphere

Front 260

Uranus and Neptune appear blue or blue-green because

Back 260

traces of methane in their atmospheres absorb red light very efficiently.

Front 261

Uranus and Neptune do not contain liquid metallic hydrogen because they

Back 261

are not massive enough.

Front 262

What causes the geological activity seen on some of the inner moons of Jupiter?

Back 262

Tidal friction as a result of being so close Jupiter heats their interiors.

Front 263

A newly formed planet or large asteroid becomes molten due to ______.

Back 263

decay of radioactive element isotopes and the last infalling objects

Front 264

If a star is found with five planets orbiting it, and a process like that described in the solar nebula theory formed the planets, which of the planets would be expected to have the greatest uncompressed density?

Back 264

The one closest to the star.

Front 265

Outgassing is

Back 265

the release of gas from rocks as they are heated.

Front 266

The asteroid belt is found between which two planets' orbits?

Back 266

Mars and Jupiter

Front 267

The first solid grains of ______ formed in hot regions near the sun. Much farther from the sun the first grains (or rather flakes) of ________also formed by a similar process as the close-in grains, _______.

Back 267

iron; water ice; condensation

Front 268

The oldest rocks found on Earth are about ____ years old.

Back 268

4.4 billion

Front 269

Which one of the following IS a characteristic of Jovian planets?

Back 269

low average density

Front 270

A spectroscopic binary shows periodic variations in its

Back 270

radial velocity.

Front 271

Convection is important in stars because it

Back 271

mixes the gases of the star and transports energy outward in the star.

Front 272

Star clusters are important to the study the stellar evolution because stars in a given cluster have the same

Back 272

age

Front 273

The lower edge of the Main Sequence band is known as ____ and represents the location in the HR-diagram at which stars begin their lives as main sequence stars.

Back 273

the zero-age main sequence

Front 274

A planetary nebula is

Back 274

the expelled outer envelope of a medium mass star.

Front 275

A Type I supernova is believed to occur when

Back 275

a white dwarf exceeds the Chandrasekhar limit.

Front 276

About how long will a 0.5 star spend on the main sequence?

Back 276

57 billion years

Front 277

If the theory that novae occur in close binary systems is correct, then novae should

Back 277

repeat after some interval.

Front 278

Massive stars cannot generate energy through iron fusion because

Back 278

both fusion or fission of iron nuclei absorb energy

Front 279

Stars in a star cluster

Back 279

all have the same age and all have the same chemical composition

Front 280

The Crab nebula is

Back 280

supernova remnant.

Front 281

The explosion of a supernova typically leaves behind

Back 281

a shell of hot, expanding gas with a pulsar at the center.

Front 282

The theory that the collapse of a massive star's iron core produces neutrinos was supported by

Back 282

the detection of neutrinos from the supernova of 1987.

Front 283

What nuclear fusion mechanism does an isolated white dwarf use to generate energy?

Back 283

White dwarfs don't generate their own energy.

Front 284

Where are elements heavier than iron primarily produced?

Back 284

Supernovae

Front 285

____ is a form of electromagnetic radiation produced by rapidly moving electrons spiraling through magnetic fields.

Back 285

Synchrotron radiation

Front 286

A group of 10 to 100 stars that formed at the same time but are so widely scattered in space their mutual gravity cannot hold them together is called

Back 286

an association.

Front 287

How does the traditional theory of the formation of the galaxy explain the origin of globular clusters?

Back 287

They formed early on during the free-fall collapse of the proto-galactic material.

Front 288

The age of the Milky Way galaxy has been estimated to be at least 13 billion years based on

Back 288

observations of globular clusters

Front 289

The chemical abundance of population I stars

Back 289

indicates that the material they formed from had been enriched with material from supernovae.

Front 290

The orbits of population I stars

Back 290

are confined to disk of the galaxy and are nearly circular

Front 291

The period-luminosity relation is useful in determining

Back 291

the distance to globular clusters that contain Cepheid variables.

Front 292

Which of the following can't be associated with the spiral arms of a galaxy?

Back 292

Metal poor stars

Front 293

Younger stars have more heavy elements because

Back 293

the heavy elements were made in previous generations of stars.

Front 294

____ of the Milky Way contains mostly old (population II) stars and globular clusters.

Back 294

The spherical halo component