Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Astronomy > Lectures 13-16 > Flashcards

Lectures 13-16 Flashcards

1
Q

How did the jovian planets form?

A
  1. frozen hydrogen compounds (ices) formed planetesimals= build up proto-planets
  2. Massive planets gravitationally attract H and He gas
  3. Solar nebula less dense further out= takes longer to accumulate mass
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe Jupiter’s internal structure.

A 
top-down:
gaseous hydrogen
liquid hydrogen
metallic hydrogen
core of rock, metals and hydrogen compounds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Does Jupiter emit more heat than it receives?

A

yes- also Saturn and Neptune

-probably due to continued contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain the red bands on Jupiter’s surface.

A 
red= lower altitude, warmer, emit more IR
white= higher altitude clouds, cooler, emit less IR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does the atmosphere of Jupiter compare to the Earth’s?

A
  • similar regions: thermosphere, stratosphere, troposphere but no surface
  • features persist longer as there is no friction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the Jupiter’s Great Red Spot?

A

-giant storm, long lived, like a hurricane but high pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Can magnetic field tell us about the internal structure of a planet?

A

-yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why is Jupiter’s magnetic field different?

A

-huge, interaction with IO that’s basically in the magnetic field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the two categories of jovian moons?

A

1: formed in accretion disk around planet, larger, regular orbits, surfaces, lots of ice
2: captured- smaller, irregular shapes, little geological activity, irregular orbits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Is Io geologically active?

A

Yes, volcanoes, lot of activity due to tidal stress.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why are the orbits of the Galilean moons elliptical?

A

because of their orbital resonances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which place in the solar system is most likely to have life?

A

Europa. -ocean?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the atmosphere of Titan.

A

Thick N2 atmosphere.

  • CH4, C2H6 give greenhouse effect
  • organic molecules
  • lakes of liquid methane and ethane
  • similar geology to Earth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Do all jovian planets have rings?

A

Yes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How thick and how wide are Saturn’s rings?

A

10 m thick

140 000 km wide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What causes the bands in the rings?

A

Bigger objects sweeping it gravitationally.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A very bright ring will be denser or less dense?

A

denser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are asteroids?

A

Rocky leftovers of planet formation.

-small more common than big ones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the name of the largest asteroid and how big is it?

A

Ceres

1000km in diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Would all the asteroids in the solar system add up to a planet?

A

No, not even a terrestrial one.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the physical characteristics of asteroids?

A

Not round, cratered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe asteroid orbits.

A

Most asteroids in the asteroid belt between Mars and Jupiter.
Trojan asteroids= follow Jupiter’s orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do we call asteroids that cross Earth’s orbit?

A

near earth asteroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How does Jupiter influence the asteroid belt?

A

Asteroids in orbital resonance with Jupiter experience periodic gravitational tugs.
=this creates gaps in the asteroid belt
-tidal forces from Jupiter prevented a planet forming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is a meteorite?

A

A rock from space that falls through Earth’s atmosphere.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is a meteor?

A

The bright trail left by a meteorite.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe a comet.

A
  • icy counterpart of an asteroid
  • nucleus is a dirty snowball
  • most comets remain in deep freeze in the outer solar system
  • comets have a tail only when they get close to the Sun and start melting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is a coma in a comet?

A

The atmosphere that comes from a comet’s heated nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is a plasma tail?

A

Gas escaping from coma, pushed by solar wind.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is a dust tail?

A

Pushed by photons. always facing away from the Sun.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How long are tails of comets approx?

A

100 000kms long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How big is an average comet?

A

10 km.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the relationship between a comet and a meteor shower?

A

The comets leave behind small particles that shower down on Earth and cause meteor showers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where were the comets first formed?

A

Between Jupiter and Neptune.

35
Q

Where did comets go after their creation and why?

A

Influence of the jovian planets gravity, some went to the inner solar system and more in to the outer solar system= Oort cloud/Kuipier cloud= deep freeze

36
Q

What is Oort cloud?

A

Region rich in comets, trillions
50 000 AU away
-comets have eccentric orbits and random tilts

37
Q

What is the Kuiper belt?

A

30-50 AU

  • about 100 000 comets more than 100km big
  • comets orbit in the same plane and direction as the planets
38
Q

How did comets come to be in the Oort cloud and Kuiper belt?

A

Oort- came from the jovian region

Kuiper- formed here

39
Q

How do comets get to the inner solar system?

A

When Kuiper or Oort disturbed gravitationally.

40
Q

When did the 3 mass extinctions occur on Earth and how much of life disappeared?

A

1- 434 million yrs ago 85% life wiped
2- 251 million yrs ago 97% life wiped
3- 65 million yrs ago 70-80 % life wiped
-know from fossil record and coral reef growth

41
Q

What role does Iridium play in telling when giant impacts occurred?

A
  • very rare on Earth, often in meteorites
  • layer of iridium 65 million yrs ago
  • dinosaur fossils all below this layer
42
Q

Where did the meteorite that killed off dinosaurs fall?

A

Mexico.

43
Q

How often is Earth hit?

A

small impacts- daily

-big ones million yrs apart

44
Q

How do light and matter interact?

A

Emission
Absorption
Transmission (transparent objects transmit ligt and opaque objects block = absorb light)
Reflection/scattering

45
Q

What does a mirror do to light?

A

Reflects it in a particular direction.

46
Q

What does a movie screen do to light?

A

Scatters light in all directions.

47
Q

Describe wavelength.

A

Distance between the two peaks.

48
Q

Frequency?

A

number of times per second that a wave vibrates up and down.

49
Q

How to calculate wave speed?

A

=wavelength x frequency

50
Q

What is light?

A

Both a particle and a wave.

51
Q

How is light a wave?

A

It is a vibration of electric and magnetic fields, it interacts with particles through these fields.

52
Q

How is light a particle?

A

Photons, each has a wavelength and frequency and its energy depends on its frequency

53
Q

what is λ?

A

λ= wavelength

54
Q

what is f?

A

frequency

55
Q

what is c? how do you get it?

A

c= speed of light = λ x f

56
Q

How do you calculate energy of a photon?

A 
E= h x f
h= Planck's constant  6.626 x 10 to -34 joules/s
57
Q

Name the parts of electromagnetic spectrum from shortest waves (highest energy).

A 
gamma rays
X rays
UV
visible
infrared
radio
(microwaves are bit of infrared and radio)
58
Q

What are the three basic types of spectra?

A
  • emission (peaks)
  • continuous (smooth)
  • absorption (dints)
59
Q

What is a continuous spectrum?

A

The spectrum of common lightbulbs, spans all visible wavelengths without interruption.

60
Q

What is an emission line spectrum?

A

A thin or low-density cloud of gas emits light only at specific wavelengths that depend on its composition and temperature, producing a spectrum with bright emission lines.

61
Q

What is an absorption line spectrum?

A

A cloud of gas between us and the light bulb can absorb light of specific wavelengths leaving dark absorption lines in the spectrum.

62
Q

Why does each element have a chemical fingerprint?

A

Each type of atom has a unique set of energy levels, each transition corresponds to a unique photon energy,frequency and wavelength.

63
Q

How do energy levels of molecules differ from atoms?

A

Molecules have additional energy and vibrational levels that can make the spectra very complicated.
-many of these interactions in the infrared part of the spectrum= ie in our atmosphere the greenhouse interactions

64
Q

What does thermal radiation depend on?

A

Temperature.

65
Q

What emits thermal radiation?

A

Nearly all large or dense objects, planets, stars, you…

66
Q

What are the properties of thermal radiation?

A
  1. Hotter objects emit more light at all frequencies per unit area.
  2. Hotter objects emit photons with a higher average energy.
    =also called Blackbody radiation
67
Q

How to interpret actual spectrum?

A

Look at where is it interrupted from interrupted. What does it emit and absorb.
If absorbs blue light= appears red
if IR peaks= what temp it is
UV emission= indicates hot upper atmosphere
What does absorb= CO2 = present

68
Q

How can light tell us speed of an object?

A

red shift moving away, the more it happens the faster it is.

blue shift= moving towards us

69
Q

What does the Doppler shift tell us?

A

Only about the part of an object’s motion towards or away from us.

70
Q

How does rotation of an object affect the spectral lines?

A

Faster rotation makes the spectral lines wider.

71
Q

What are the 3 main parts of a telescope?

A
  • collecting area: bigger is better= more photons
  • focusing device: depends on wavelength (mirror curved= visible, nested mirror= X ray)
  • detector- records photons
72
Q

What is resolution?

A

How close can two 2 images be and appear distinct?

73
Q

How does the size of collecting area effect resolution?

A

The bigger the area= the smaller the separation images you can resolve.

74
Q

How does wavelength affect effect resolution?

A

Longer wavelengths= worse resolution

-can see blue better than red wavelengths

75
Q

How does the atmosphere (visible light) and ionosphere (for radio waves) effect the resolution?

A

WIggle causing!

76
Q

What is seeing in atmosphere?

A

Movement of the light as it comes through atmosphere

77
Q

What are the effects of seeing?

A

twinkling stars-seeing makes the photons dance around as go through atmosphere
sunset red= more atmosphere for the light to go through

78
Q

Why do planets not twinkle?

A

Because they are bigger for us, too big for the seeing to have an effect.

79
Q

Why do we have mostly optical and radio telescopes on Earth?

A

They are the wavelengths that get here through the atmosphere.

80
Q

How do we know that the Earth is spinning on its axis?

A

Open shutter of a telescope=for hours= see the stars move

81
Q

What is an analemma?

A

The movement of the Sun around the sky- makes figure eight= demonstrates that we don’t orbit the Sun in a circle

82
Q

What is the position of the Sun, Moon and Earth at lunar eclipse?

A

Earth passes between the Sun and the Moon, so the Earth’s shadow passes across the Moon.

83
Q

What is the position of the Sun, Moon and Earth at solar eclipse?

A

Moon passes between the Earth and the Sun blocking out the Sun

84
Q

How do we predict eclipses?

A

The Saros cycles= every 18 years, 11.3 days Earth,Moon and Sun return to the same symmetry
-not easily predictable where it will be visible from fully or partially

Astronomy (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions