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Earth Science > Unit 4B > Flashcards

Unit 4B Flashcards

1
Q

What is the most powerful force in the solar system?

A

The Sun’s gravity

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2
Q

What percent of the solar system’s mass is contained in the sun?

A

99.8%

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3
Q

What can happen in the Sun’s core?

A

Nuclear fusion, the fusion of two atomic nuclei.

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4
Q

What elements are fused in the Sun’s core, and what is the result?

A

Hydrogen; Helium, heat, and light

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5
Q

How old is the sun, and how long will the hydrogen in the sun’s core last for?

A

5 billion years; 10 billion years

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6
Q

What are the parts of the interior of the sun, and how do they transmit energy?

A

Core; generates it via nuclear fusion
Radiative zone: radiation in the form of X rays travel through here for about 1 million years
Convective zone: energy is transferred by convection

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7
Q

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

A

Photosphere: The surface of the sun; generates light
Chromosphere: “Color sphere” produces red glow
Corona: A white halo around the sun

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8
Q

Why isn’t there life on any other planets in our solar system?

A

Because either too much or too little heat energy reaches them for life as we know it to exist.

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9
Q

What are sunspots?

A

Darker, cooler areas on the sun’s surface.

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10
Q

Is sunspot concentration constant?

A

No, it is cyclical, in a 10-11 year cycle

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11
Q

How does sunspot concentration affect temperatures on earth; and what time in earth’s history supports this?

A

Low sunspot concentration makes lower temperatures; Little Ice Age.

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12
Q

What are solar prominences?

A

Solar prominences are loops of gas in the corona linking sunspots.

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13
Q

What happens if two solar prominences connect?

A

They heat up to high temperatures before exploding as a solar flare.

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14
Q

What do solar flares do to solar wind?

A

They greatly increase it, increasing the number of particles that reach earth, which results in a magnetic storm.

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15
Q

What is solar wind?

A

A stream of electrically charged particles

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16
Q

What happens during a magnetic storm?

A

Auroras may be visible in lower latitudes. It is possible that compass readings may be inaccurate as these charged particles enter earth’s atmosphere. Land-based telephone systems, as well as satellite-controlled cell phone systems, can be disrupted by a magnetic storm. Magnetic storms can cause electrical problems and interrupt air travel.

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17
Q

What causes auroras?

A

When electrically charged particles from the sun sneak in past the magnetic field and atmosphere. causing the gas molecules to glow.

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18
Q

How long does it take the moon to revolve around the earth? How long does it take to rotate?

A

27.3 days

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19
Q

What causes the moon’s phases?

A

Only half of the moon is exposed to sunlight; the parts of the moon visible on earth changes, causing phases

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20
Q

How long does it take for a moon to go through all its phases?

A

29.5 days

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21
Q

Does the moon always rise and set at the same time?

A

No, it rises and sets with the sun during new moon; sets when the sun rises and rises when it sets during full moon.

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22
Q

When is the moon new? When is it full?

A

When it is between the earth and the sun; when it is behind the earth.

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23
Q

Different moon phases, in order, with rising/setting times.

A

New moon: Rises at dawn, sets at dusk
Waxing crescent: Rises shortly after dawn, sets shortly after dusk
First quarter: Rises at noon, sets at midnight
Waxing gibbous: Rises in the later afternoon, sets early in the morning
Full moon: Rises at dusk, sets at dawn
Waning gibbous: Rises shortly after dusk, sets shortly after dawn.
Last quarter: Rises at midnight, sets at noon
Waning crescent: Rises early in the morning, sets in the later afternoon

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24
Q

In what direction does light seem to be filling/leaving the moon?

A

Right to left

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25
Q

What causes a solar eclipse?

A

When the moon is directly between the earth and the sun

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26
Q

Why doesn’t a solar eclipse happen every month?

A

Because the moon and earth orbits aren’t aligned, so the moon rarely comes between the earth and the sun.

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27
Q

Parts of a shadow of a solar eclipse:

A

Umbra: The darkets part, if you are in the umbra during solar eclipse, then the sun gets totally blocked
Penumbra: larger but brighter pat, if in penumbra then part of sun is still visible

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28
Q

What is a lunar eclipse?

A

When the earth’s shadow falls onto the moon.

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29
Q

Are lunar eclipses also partial and total?

A

Yes

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30
Q

Eclipses can be predicted

A
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31
Q

What shape is the orbit of the moon around the earth?

A

Elliptical

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32
Q

What is it called when the moon is closest to the earth, and what phase is it in then? Farthest from the earth?

A

Closest: Perigee, new
Farthest: Apogee, full

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33
Q

How many degrees does the moon rotates around the earth in one day?

A

13.2 degrees

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34
Q

How much earlier/later does the moon rise/set each day?

A

50 minutes later.

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35
Q

What causes the tides?

A

The gravity of the moon and sun

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36
Q

Why does gravity cause tides?

A

The moon pulls water to itself, causing a bulge; then a bulge occurs on the opposite side since the earth is pulled more than the water.

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37
Q

Does the phase of the moon have an impact on the tides?

A

Yes

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38
Q

When do spring and neap tides occur?

A

Spring: When the moon is in line with the sun; high tides are higher, low tides are lower; full, new
Neap: When the moon is at a right angle to the sun; high tides are lower, low tides are higher; first quarter, last quarter

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39
Q

What can influence tides?

A

The phase of the moon; how far it is from the earth

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40
Q

Is earth’s orbit around the sun elliptical?

A

Nope

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41
Q

What is it called when the earth is closest to the sun, and when is it? Farthest from the sun?

A

Closest: Perihelion, January
Farthest: Aphelion, July

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42
Q

How much is the earth’s axis tilted? Where is it pointing?

A

23.5 degrees; north star

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43
Q

When is the earth tilted towards the sun, and what is the day called? Not towards or away from the sun? Away from the sun?

A

Away: Winter solstice (North), summer solstice (south), Dec 21
Not toward/away: spring equinox, Mar 21, and fall equinox, Sep 21
Toward: Summer solstice (North), winter solstice (south), Jun 21

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44
Q

How does the apparent path of the sun change?

A

It will go higher or lower in the sky, and the amount of day/night time changes.

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45
Q

How did ye olden-day scientists think the solar system formed?

A

Descartes: The universe spun, and stars and planets formed from this spinning material
Kant: Gravity would cause a spinning cloud of gas and dust to flatten into a disk.
Laplace: A spinning cloud of gas and dust would cool and shrink, leaving material behind to form planets.
Buffon: A comet hit the sun; the pieces flew off to form planets.
Moulton and Chamberlin: A large star passed near the sun; its gravity pulled of blobs of material that formed planets.

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46
Q

What is the modern theory of the origin of solar systems?

A

Nebular hypothesis
A large cloud of gas (hydrogen) and dust, a nebula, begins to collapse under its own gravity or some gravitational perturbation–for example, a nearby star or supernova.
The collapsing cloud begins to spin.
The spinning, collapsing cloud flattens into a rotating disk.
As in the pie pan demonstration that you just conducted, material in the disk begins to accumulate in the center.
As the material coalesces in the center, it becomes dense, compresses, and heats up.
More and more material coalesces to form a protostar

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47
Q

What support is there for the nebular hypothesis?

A

The Hubble space telescope sees evidence of it in M33 as circumstellar disks

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48
Q

What happens after a protostar forms?

A

It accumulates material until it can start the process of nuclear fusion; then, no new material can accumulate

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49
Q

How do planets form?

A

Matter away from the protostar clump together to form planetesimals, and collide with each other to form planets

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50
Q

Why don’t the planets collapse to the center?

A

The spin keeps them spinning around the star in the center, as long as the spin is right; too much spin, planets go away; too little spin, planets crash into the star

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51
Q

What happened to the lighter clumps of rock in our solar system?

A

They formed two regions at the edge of our solar system, the Oort Cloud and the Kuiper Belt

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52
Q

What do you call it when a planet moves forward? Backwards

A

Posigrade, Retrograde

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53
Q

What was Ptolemy’s model? How does it explain loopy behavior in planets’ orbits?

A

Geocentric
Placed planets on circle that orbit the earth, that the planets follow

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54
Q

What was Copernicus’ model? How does it explain loopy behavior in planets’ orbits?

A

Heliocentric
planets orbit the sun at different speeds, sometimes a planet will overtake another planet as it orbits. When that happens, the slower planet looks as if it moves backward before continuing on its path

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55
Q

What did Kepler believe the orbits were? Who did he work with for data?

A

Nested, regular geometric forms; Tycho Brahe

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56
Q

What are Kepler’s laws of planetary motion?

A

1: Orbits of planets are in the shape of an ellipse with the sun at one focus.

#2: Planets move faster when closer to the sun, slower when farther from the sun.
#3: The farther a planet is from the sun, the longer it takes to complete one orbit.

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57
Q

How did Newton explain the orbits of the planets?

A

Gravity

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58
Q

How did others use Newton’s laws of orbit?

A

Edmund Halley used it to predict when Halley’s comet would next return

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59
Q

What is the center of our solar system?

A

The sun

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60
Q

What do all planets in our solar system share with each other?

A

The orbit the sun in the same direction and in the same plane

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61
Q

What are the three groups of planets?

A

Terrestrial: Inner planets made of rock and metal
Gas giants: Outer planets made of gas, ice and dust
Dwarf planets: Planets with enough gravity to be round

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62
Q

Where are most of the asteroids in our solar system? Which way do they orbit?

A

Between Mars and Jupiter; same way as planets

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63
Q

Where do comets come from?

A

Kuiper Belt and Oort Cloud

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64
Q

Where are the Kuiper Belt and Oort Cloud?

A

Beyond the orbits of the outer planets

65
Q

How do comets travel?

A

From the outer solar system to the inner solar system and back

66
Q

Parts of a comet.

A

Ion Tail: Ions pushed away by solar winds
Nucleus: Main part of a comet
Coma: Haze of sublime gas immediately around the nucleus

67
Q

Why was Pluto demoted to dwarf planet?

A

It is a tiny rocky body in a place inhabited by gas giants; it’s orbit is inclined; its orbit comes inside Neptune’s; its moon is nearly as big as itself; other objects have been discovered as large as or bigger than Pluto

68
Q

What planets have no moons?

A

Mercury and Venus

69
Q

Can asteroids have moons?

A

Yes

70
Q

How can moons originate?

A

When debris knocked off a planet coalesces into a moon; when asteroids are captured by a planet’s gravity

71
Q

What is debris that hits earth’s atmosphere called? What is debris that survives and lands on earth’s surface called?

A

Meteor; meteorite

72
Q

What happens when earth’s orbit crosses that of a comet?

A

We see showers of meteors

73
Q

Do other stars have planetary systems?

A

Yes

74
Q

What makes a planet a planet?

A

Orbits a star, but is not a star or satellite of another planet
It has sufficient gravity to make itself round
Its gravity is also sufficient to clear its orbit of other debris

75
Q

Compare gas giants and terrestrial planets by size, mass, density, gravity, temperature, and rings.

A

Gas giants have more volume and mass. and thus more gravity (they also have rings), but terrestrial planets are denser and warmer

76
Q

How do we know what planets are made of?

A

Calculation of density and examining characteristics of light given off by the planet

77
Q

What planet has the greatest tilt? Which planets rotate clockwise?

A

Uranus; Uranus and and Venus

78
Q

What planets have no moons?

A

Mercury and Venus

79
Q

What do planetary impacts form?

A

Craters, mountain ranges

80
Q

What theories were originally proposed for the formation of the moon?

A

It accreted along with the earth; it spun off while the earth formed; the earth’s gravity captured it

81
Q

How did the moon actually form?

A

A planetary impact by a Mars-sized object knocked part of the earth off to form the moon

82
Q

Why could planetary impacts cause mass extinctions?

A

They would send high amounts of material into the atmosphere that would block sunlight, that would kill of plants and the animals that eat them, and would cool the earth

83
Q

Have impacts caused mass extinctions of life on earth?

A

Yes; 65 million years ago there were mass extinctions, and there was iridium around that time coming from asteroids

84
Q

What provided proof of planetary impacts?

A

When fragments comet Shoemaker Levy 9 collided with Jupiter in 1994

85
Q

What is the Near Earth Object Program?

A

A program that catalog possibly problematic near earth objects

86
Q

What is light?

A

Electromagnetic energy that behaves as a transverse wave

87
Q

What are properties of a wave?

A

Crest (top part of a wave)
Trought (bottom part of a wave)
Wavelength (distance from crest to crest or trough to trough)
Frequency (number of waves that pas a given point in a given time interval)
Velocity (how fast the wave travels)

88
Q

What are the spectrum of light?

A

Visible light, infrared, ultraviolet, microwave, radio, x ray, gamma ray

89
Q

How are the wavelength, frequency, velocity, and energy of a light wave related?

A

The velocity of light is equal to the wavelength times the frequency
The energy is equal to Planck’s constant times the velocity of light, and then divided by the wavelength, or Planck’s constant times the frequency

90
Q

What is Planck’s constant equal to?

A

6.626 x 10-34 joules

91
Q

What is the relationship between temperature and maximum wavelength, and what is it called?

A

the maximum wavelength is equal to 0.2897/T, where T is the temperature in Kelvin; known as Wien’s Law

92
Q

What can the light given off by a hot object tell about the object in addition to temperature?

A

the chemical composition (different colors=different chemicals)

93
Q

How is color of light given off by hot objects used by astronomers?

A

If the light of a star is passed through a prism/diffraction grating, discrete lines of emission appear that correspond to the elements within that star

94
Q

What is absorption line spectrum, and how does it compare to emission line spectrum?

A

Absorption line spectrum is the spectrum that appears after a white light passes through gases; the black lines are the colors absorbed by the gas
The black lines correspond to the colors the gas would emit in the emission line spectrum

95
Q

What colors will light become when Doppler effected?

A

Light will blue shifted if going toward you, red-shifted if going away from you; amount of shift is proportional to the velocity of the moving object

96
Q

What is it called when light bounces off an object? Is bent by the object when passing through it?

A

Reflection; refraction

97
Q

How is reflection and refraction used in astronomy?

A

Used by telescopes to collect light from a large area and focus it

98
Q

What is a telescope?

A

An instrument that collects light and brings it to a point

99
Q

Parts of a telescope:

A

Objective lens or primary mirror collects and focuses light
Magnifier spreads light from the focus onto an imaging device, which records the light collected and magnified by the telescope

100
Q

What are the parts of refracting telescopes?

A

Objective lens: Long-focal-length lens that collects and brings light to a focus
Eyepiece: Smaller-focal-length lens that magnifies and spreads out light to fill the detector
Tube: Holds the two lenses at the correct distances apart and keeps out dust and air current
Mount: Holds and moves the telescope

101
Q

What are the parts of reflecting telescopes?

A

Primary mirror: Long-focal-length mirror collects and brings light to a focus
Secondary mirror: deflects light outside of the tube to the eyepiece
Eyepiece: Smaller-focal-length lens that magnifies and spreads out light to fill the detector
Tube: Holds mirrors and eyepiece at correct distances apart and keeps out dust and air current

102
Q

How do x-ray telescopes bring x-rays to a focus?

A

They make them hit mirrors at small enough angles to bounce off them and be brought to a focus

103
Q

How do radio telescopes work?

A

They use a large dish to reflect light to a mirror to reflect it to a focus

104
Q

Scientists have designed telescopes to collect light from each part of the spectrum

A
105
Q

What are adaptive optics, and how do they work?

A

A technology that eliminates distortion caused by earth’s atmosphere; a wavefront sensor senses the distortion of light in real time and sends that information to the wavefront corrector, which uses hundreds of tiny actuators to deform the surface of the mirror to distort the light in a way that cancels the distortion of the aerth’s atmosphere

106
Q

Why are space telescopes needed?

A

Some wavelengths of light are absorbed/reflected by the earth’s atmosphere, so the only way to record those wavelengths is with telescopes outside the earth’s atmosphere

107
Q

What measure of distance is used within our solar system?

A

AUs (Astronomical Units)

108
Q

How far is 1 AU?

A

The average distance from the earth to the sun, 150 million km

109
Q

What measure of distance is used in space?

A

Light-years

110
Q

How far is a light-year?

A

36000 AUs

111
Q

What is the second farthest star? How far away is it?

A

Proxima Centauri; 4.3 light-years

112
Q

How far away is the brightest star? How far away is the North Star? What are their names?

A

9 light-years; 700 light-years; Sirius; Polaris

113
Q

What is parallax, and when is it unusable?

A

The apparent change in position of an object as it is viewed from different positions; 1000 light-years from earth

114
Q

How does parallax compare to distance from Earth?

A

The smaller the parallax, the farther from earth

115
Q

How are parsecs calculated?

A

Look at a star on March 21, then on September 21; find the angle of arc it moved; then divide 1 by that angle to get the parsec

116
Q

What are the three major classifications of stars?

A

Low mass (<1-2 solar masses)
Intermediate mass (2-8 solar masses)
High mass (>8 solar masses)

117
Q

What two forces constantly work against each other throughout a stars life?

A

Thermal pressure and gravity

118
Q

Properties of low, intermediate, and high mass stars:

A

Low: cool temperature, dim brightness, 10,000-200,000 million-year lifespan
Intermediate: intermediate temperature, intermediate brightness, 1,000-10,000 million-year lifespan
High: hot temperature, bright brightness, 10-100 million-year lifespan

119
Q

How do low-mass stars die?

A

They can run out of fuel, and collapse into a white dwarf that is small and cool; the outer shell’s hydrogen might also fuse, to expand the outer shell, and then helium fuses to carbon the expand even bigger, before shedding that outer shell and leaving a white dwarf

120
Q

How do high-mass stars die?

A

They collapse in several stages, going from helium->carbon->oxygen->neon->silicon->magnesium->sulfur->iron, before heating up immensely and collapsing and then exploding as a supernva; depending on the mass. the remains of the star might either be a neutron star or black hole; bigger than 3 solar mass core makes a black hole, otherwise begins neutron star

121
Q

What determines the brightness of a star?

A

Its luminosity (the higher the luminosity, the brighter the star) and distance from earth (the farther from earth, the dimmer the star)

122
Q

What determines the luminosity of a star?

A

The more massive the star, the more luminous the star

123
Q

What determines the color of a star?

A

The temperature; in increasing temperature, red, orange, yellow, white, blue

124
Q

How can absorption spectrums be used in astronomy?

A

The light that is absorbed hints at what elements are part of the star’s cooler atmosphere

125
Q

How are stars classified according to their spectra?

A

They are classified from O to M, with O being hottest and M being coolest; and subclassified from 0-9

126
Q

What is the Hertzsprung-Russell diagram?

A

A diagram that relates luminosity and color; most lie on a line that goes from the upper left to bottom right

127
Q

What is the fusion of hydrogen to helium called?

A

Proton-proton fusion (p-p fusion)

128
Q

How does p-p chain fusion work?

A

Proton+Proton=Deuterium (proton-neutron), positron, neutrino
Deuterium+Proton=He-3, gamma ray
He-3+He-3=He-4, Proton, Proton

129
Q

What is the fusion of helium called?

A

Triple alpha process

130
Q

How does triple alpha process work?

A

He-4+He-4=Be-8, gamma ray
Be-8+He-4=C-12, gamma ray

131
Q

What fusion occurs in high-mass stars?

A

Carbon-nitrogen-oxygen fusion (CNO fusion)
Helium capture

132
Q

How does the CNO fusion work?

A

It is a cycle
C-12+Proton=N-13, gamma ray
N-13=C-13, positron, neutrino
C-13+Proton=N-14, gamma ray
N-14+Proton=O-15, gamma ray
O-15=N-15, positron, neutrino
N-15+Proton=C-12, He-4

133
Q

How does helium capture work?

A

C-12+He-4=O-16
O-16+C-12=Si-28
Si-28+Si-28=Fe-56

134
Q

How do we know nuclear-fusion reactions happen inside stars?

A

Use the principles of physics and mathematics to model the processes involved. These models predict the types of particles and energies of radiation emitted by stars. Astrophysicists then make observations using gamma-ray telescopes, X-ray telescopes, spectroscopy, and neutrino detectors.

135
Q

Where do most of the stars of the Milky Way lie?

A

A flat disk that orbits the galactic nucleus

136
Q

Parts of the Milky Way galaxy

A

Galactic Nucleus - the center
Galactic bulge - a spherical bulge around the galactic nucleus
Arm - spiral arms
Halo - spherical region above and below that orbits the nucleus

137
Q

What are the three types of galaxies?

A

Spiral and barred spiral
Elliptical or round
Irregular

138
Q

What are spiral galaxies?

A

Spiral galaxies have a prominent nuclear bulge and several spiral arms made up of gas, dust, and young stars

139
Q

What are barred spiral galaxies?

A

Barred spiral galaxies have a bar running across the center of the galaxy with stars emerging from it

140
Q

What is the difference between disk and halo stars?

A

Disk stars tend to be young and rich in metals, while halo stars tend to be older and poorer in metals

141
Q

What are elliptical galaxies?

A

Galaxies with stars that orbit the galactic nucleus randomly in three dimensions; typically have older, poor in metal stars

142
Q

What are irregular galaxies?

A

Galaxies that can vary widely in shape, but aren’t spiral or elliptical galaxies; have young and old stars in irregular orbits, and often orbit other galaxies

143
Q

How do galaxies form?

A

Small concentrated areas of gas and dust collapse under gravity, attract more gas and dust, and grow into protogalactic clouds, which then collide and merge to form galaxies

144
Q

Why do galaxies become spiral/elliptical galaxies?

A

Spiral because more spin, elliptical because more mass

145
Q

Why can some objects be unseen?

A

They may be obscured by interstellar dust; or be too far away or too small to be seen

146
Q

How can objects obscured by dust be seen?

A

By looking at it in multiple wavelengths, since other wavelengths can penetrate dust

147
Q

How can very small objects be seen?

A

If a visible star wobbles, that means that smaller objects must be orbiting it; the wobbles can indicate the objects mass, velocity, or period

148
Q

How can extrasolar objects be detected?

A

By looking at the Doppler shift of a star’s spectra, and the increase/decrease of light emitted by the star; if the light increases/decreases, then something passes in front of it periodically, decreasing the light that reaches earth

149
Q

How can black holes be detected?

A

By their effects on companion star’s, like their wobble; or jets of matter ejected by the black hole

150
Q

What is cosmology?

A

The study of the origins and fate of the universe

151
Q

What are Cepheid variable stars used for?

A

A candle to find distance in space

152
Q

What did Edwin Hubble discover?

A

Cepheid variable stars were always red shifted, and the farther the galaxy the star was in, the faster it was moving away, and no matter what direction he looked, the galaxies were always moving away

153
Q

What happened when radio astronomers examined the sky in the microwave region?

A

They found it was relatively uniform, and it was glow that remained from the early universe

154
Q

If you look backwards, what do you find out about the early universe?

A

It was hot and small

155
Q

What forces existed in the early universe?

A

Only one superforce

156
Q

What happened in the beginning of the universe, and when?

A

1 sec: Protons and neutrons
100 sec: They combine to form hydrogen and helium nuclei
Few hrs: Hydrogen and helium production stops
300,000 yrs: Electrons begin combining with them to from hydrogen and helium atoms
Few million yrs: Expansion slows locally
200 millions yrs: Clouds of gas begin to be hot enough to star nuclear fusion reactions
4 billion years: Stars clump together to form galaxies
9 billion yrs: Our solar system forms

157
Q

What are the epochs?

A

Atomic epoch: atoms could form
Galactic epoch: New galaxies could form
Stellar epoch: Galaxies can’t form anymore, but stars still can

158
Q

What does the big bang theory explain?

A

Why cosmic background microwave radiation is uniform on a large scale, why the minimum ratio of hydrogen to helium (3:1) is observed, and why the universe is expanding

Earth Science (10 decks)

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