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Flashcards in Midterm Deck (78):
1

why is it generally hotter in summer than in winter

sun is higher in the sky
more hours of daylight in the summer

2

Degree of earth's tilt

23.5 degrees
-this is what causes seasons on earth

3

a planet with the most extreme seasons would have a tilt of...

near 90 degrees

4

at noon, which phase of the moon can be seen?

New moon

5

When the Moon is seen as full in Seattle, what is the phase of the Moon as viewed twelve hours later from the opposite side of the Earth?

Also full
-same phase is seen all over earth

6

What conditions must exist for a solar eclipse to occur?

The phase of the Moon must be new and the Moon must be passing through Earth’s orbital plane.

7

What conditions must exist for a lunar eclipse to occur?

The phase of the Moon must be full and the Moon must be passing through Earth’s orbital plane.

8

partial lunar eclipse

moon only passes through penumbra or a portion of the umbra of EARTH

9

partial solar eclipse

occurs in the penumbra of the moons shadow on earth

10

TOTAL solar eclipse

path of totality only occurs within the moons umbra

11

eccentricity definition

ratio of the distance from ellipses center, to its foci
divided by length of semimajor axis

0=perfect circle
1=straight line

12

Kepler's 2nd law in relation to eccentricity

Highly eccentric orbit: planets speed up as they near the sun, and slow down at the furthest

13

Consider two planets, A and B, orbiting a distant star. Planet B orbits twice as far from the star as Planet A does. How does planet B's orbital period compare to Planet A's?

more than twice as long

14

Kepler's 3rd law: period radius rule

Period^2 = Radius^3

15

Two object have orbits around the Sun with the same semi-major axis but very different eccentricities, which has the longest orbit?

They have the same period, since they have the same semimajor axis (radius)

16

The Kepler spacecraft has discovered about a thousand planets by catching them when they pass directly in front of their star. From this data we can tell how long it takes for the planet to orbit its star. Two such planets, Kepler-62e and Kepler-62f, orbit the same star. Kepler-62e orbits in 122 days, while Kepler-62f takes 267 days. Which planet's orbit has the larger semi-major axis?

Kepler 62-f

17

If Jupiter was much less massive, its orbit would take ______ time than it does now.

the same

18

Gravity equation

Fg = G m1m2
-----------
R^2

AND

Force proportional to 1/R^2

19

Consider the force between the Sun and the Earth. If the Sun suddenly moves two times farther away, the force,

changes to 1/4 as much

20

Consider the force between the Sun and the Earth. If the Sun suddenly moves two times farther away and also doubles its mass, the force,

changes to 1/2 as much

21

Consider the force between the Sun and the Earth. If the Sun suddenly doubles its mass but the Earth changes to only half its mass, the force

Stays the same

22

How would the force of gravity on you change if the Earth's mass suddenly doubled, but its diameter stayed the same?

it would double

23

How would the force of gravity on you change if the Earth's diameter suddenly doubled, but its mass stayed the same?

changes to 1/4 as much

24

In general, we can definitely measure the mass of,

a planet with a moon
or
a moon with a space craft orbiting it

25

continuous spectrum

opaque bodies emit these (no medium to pass thru)

26

emission spectrum

Hotter gas emits sequence of bright lines (against all black)

27

absorption spectrum

colder gas in front of hotter opaque body produces continuous spectrum with dark lines superimposed

28

Shortest-->longest wavelength

gamma rays
x-rays
ultra violet
visible light
infared
radio

29

Lowest-->highest frequency

radio
infared
visible light
ultra violet
x-rays
gamma rays

30

highest-->lowest energy

gamma rays
x-rays
ultra violet
visible light
infared
radio

31

Which form of light has the highest speed?

they all have the same speed (speed of light is constant)

32

Consider the following four stars:

Star Distance Luminosity (LSun)
A 1. 2
B 2. 4
C 2 2
D 3. 1

(LSun is luminosity measured relative to the Sun, so star with a luminosity of 2 LSun is twice as bright as the Sun).


Which star is the most luminous?

B is the most luminous

33

Star Distance Luminosity (LSun)
A 1. 2
B 2. 4
C 2 2
D 3. 1

(LSun is luminosity measured relative to the Sun, so star with a luminosity of 2 LSun is twice as bright as the Sun).

For the same four stars, which is dimmest in the sky?

D is the dimmest

34

Star Distance Luminosity (LSun)
A 1. 2
B 2. 4
C 2 2
D 3. 1

(LSun is luminosity measured relative to the Sun, so star with a luminosity of 2 LSun is twice as bright as the Sun).

which is the brightest?

A is the brightest

35

Star Distance Luminosity (LSun)
A 1. 2
B 2. 4
C 2 2
D 3. 1

(LSun is luminosity measured relative to the Sun, so star with a luminosity of 2 LSun is twice as bright as the Sun).

At which distance would Star B be equal in brightness to the dimmest star?

6

36

Inverse square law for light

B = L/(4piD^2)

37

luminosity

how bright star ACTUALLY is

38

brightness

how bright star appears from earth

39

The temperature of an object emitting thermal radiation is related to the wavelength of the peak of its spectrum

As the temperature increases, the peak of the spectrum shifts toward shorter wavelengths.

40

Notice that the Sun’s spectrum appears brightest (or most intense) in the yellow-green region. This fact tells us

the appx temperature of the suns surface

41

Which of the following best describes why the Sun’s spectrum contains black lines over an underlying rainbow?


The Sun’s hot interior produces a continuous rainbow of color, but cooler gas at the surface absorbs light at particular wavelengths.

42

Suppose we want to know what the Sun is made of. What should we do?

Compare the wavelengths of lines in the Sun’s spectrum to the wavelengths of lines produced by chemical elements in the laboratory.

43

r magnitude

brightness
*high magnitude = lower brightness

(brightest star will be in the negatives

44

g-r magnitude

high g-r = redder star

low g-r = bluer star

45

materials made up in solar nebula ranked from highest-->lowest abundance

1. hydrogen & helium gas
2. hydrogen compounds
3. rock
4. metals

46

materials made up in solar nebula based at temp which each would condense into a solid (highest-->lowest temp)

1. metals
2. rock
3. hydrogen compounds
4. hydrogen & helium gas

47

Hydrogen and helium gas never condense under conditions found in the solar nebula. The remaining three categories of material in the solar nebula are shown again here. Rank these materials from left to right based on the distance from the Sun at which they could condense into a solid in the solar nebula, from farthest to closest.

Furthest:
hydrogen compounds
rock
metal
closest:

48

The material that makes up the sun was once made of

-another star
-a molecular cloud
-a protostar

49

the composition of the solar nebula is likely similar to

the sun

50

the solar systems orbits & planets rotate (mostly) in the same direction because...

of the angular momentum of the original solar nebula

51

what is NOT EVIDENCE of the solar nebula model of the formation of the solar system

earth has a relatively large amount of water

52

what evidence is there of the solar nebula model of the formation of the solar system

-all planets orbit the sun in the same direction & in a similar plane
-gas giants are in the outer system
-we observe disks around newly formed stars

53

Based on the leading scientific theory of solar system formation, which of the following statements best explains why Uranus and Neptune have a significantly different composition and higher density than Jupiter and Saturn?

jupiter and saturn captured more gas from solar nebula than uranus and neptune

54

Solar nebula theory predicts that water is...

concentrated in the outer solar system

55

3 types of planets:

1. terrestrial: composed mostly of solid material
2. Gas giants: made primarily of He & H
3. Ice giants: frozen elements & gas elements

56

Process by which planets were built

sun-->rock....gas....ice

57

habitable zone

distance from star at which liquid water could exist at the surface

-surface of planets temp must lie b/w waters freezing and melting temps

58

Key points of our Solar System

1. planets tend to orbit in same direction (& same as parent star)

2. planets tend to orbit in disklike formation (same plane)

3. planets highly differentiated in composition/location
(inner = rocky/dense, outer = low density, gaseous/icy)

4. significant debris from era of planet construction remains in SS

59

Exoplanet key points

1. they can migrate
2. they can exist in highly eccentric orbits

60

condensation theory

planetary systems born when spinning cloud of gas/dust collapses under its own weight

61

Drake equation

theoretical calculation of how many intelligent, tech advanced civilizations exist in the galaxy

-# STARS in galaxy
-# PLANETS orbiting each star
-fraction of planets within HABITABLE ZONE
-fraction of planets that LIFE EVOLVED
-fraction of planets who have INTELLIGENT life
-fraction of lifespan retention of life by fraction of stars life

62

HR diagram X and Y axis

X axis: temp from HIGH --> LOW
Y axis: luminosity from LOW-->HIGH

63

HR diagram radius of stars pattern

lower left = smaller stars
upper right = largest stars

64

Spectral classification

O--no absorption lines = hottest stars
B
A
F
G
K
M--most absorption lines = coolest stars

65

main sequence stars

Hydrogen burners
middle aged
(most stars exist here)

66

life expectancy-mass relationship

the brighter and bigger the star, the shorter the life
-burns through fuel faster

67

supernovas

death of massive stars

68

what arrangement of stellar types is in order of strength of H-lines from strongest-->weakest

A
B
F
G
K
M
O

69

arrangement of stellar types in order of temp from hottest-->coolest

O
B
A
F
G
K
M

70

stellar types order from reddest-->bluest

M
K
G
F
A
B
O

71

stellar types in order of main sequence size from smallest-->largest

M
K
G
F
A
B
O

72

clusters of HR diagrams pattern

younger stars will follow main sequence (not many diversions

older stars indicate lots of 'turn off' stars

73

Turn off point and age

Turn off point (b-v) = age of the star
ex. 0.5 b-v value = 5 gyr

74

stellar end point of low mass star

white dwarf`

75

stellar end point of high mass star

neutron star

76

stellar end point of extremely high mass star

black hole

77

Which of the following objects could be associated with the evolution of a high-mass star?

pulsar
supernova remnant

78

spectra of stars pattern

can tell what they are made of

absorption lines point down
emission lines point up