P2: Space Flashcards

(34 cards)

1
Q

What is in our star

A
  • Sun (a star)
  • 8 planets
  • Dwarf planets
  • Natural satellites (moons)
  • Asteroid belt (Mars and Jupiter)
  • Comets (frozen rocks that move around the sun in ellipitcal orbits)
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2
Q

What is the order of the planets

A
  • Mercury
  • Venus
  • Earth
  • Mars
  • Jupiter
  • Saturn
  • Uranus
  • Neptune

My Very Excited Mother Just Served Us Noodles

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3
Q

Where is our solar system

A

Milky way galaxy

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4
Q

What is the life cycle of the star

A
  • Nebula –> Protostar –> Main sequence star
  • (smaller, like our sun) Red giant –> white dwarf –> black dwarf
  • (bigger than our sun) Red Super Giant –> Supernova
    • (smaller) –> neutron star
    • (bigger) –> black hole
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5
Q

What is a nebula

A
  • Cloud of dust and gas
  • Pulled together by gravitational attraction
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6
Q

How is a protostar formed

A
  • Particles in a nebula get faster and collide more
  • Gas warms up and becomes hot enough to glow
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7
Q

How is a main sequence star formed

A
  • As a protostar becomes more dense more collisions take place
    • it gets hotter
  • It gets hot enough for hydrogen to fuse
    • forming helium
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8
Q

Why does a main sequence star remain a main sequnce star

A
  • Gravitational attraction pulling on the gas (gravity)
  • is balanced (equilibrium)
  • by the outward force of radition (radiation pressure) from nuclear fusion in core
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9
Q

What stage is our sun at

A
  • Main sequence star
  • formed 4.5 billion years ago
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10
Q

Why do we have uranium

A
  • Uranium and heavy elements
  • formed in supernova from susion
  • sun must have formed from remnants of supernova
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11
Q

How are red giants formed

A
  • Star will start to run out of hydrogen to fuse
  • core collapses
  • outer layers swell
  • cool down
  • Helium and light elements fuse in the core of a red giant
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12
Q

How are white dwarfs formed

A
  • Helium and light elements fuse in the core of a red giant
  • No more light elements available
    • fusion stops
    • no more radiation
  • star collapses
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13
Q

How are black dwarfs formed

A
  • White dwarfs
  • fade out
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14
Q

How are red super giants created

A
  • A massive (bigger than our sun) main sequence star runs out of hydrogen to fuse
  • core collapses
  • outer layers swell
  • cool down
  • Helium and light elements fuse in the core of a red super giant
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15
Q

How are supernovas created

A
  • Helium and light elements fuse in the core of a red super giant
  • No more light elements
    • fusion stops
    • no more radition
    • collapses –> Super nova
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16
Q

How are neutron stars formed

A
  • Explosion of supernova
  • compresses the (small) core into a nuetron star
  • dense and made of only neutrons
17
Q

How are black holes formed

A
  • explosion of supernova
  • if supernova was MASSIVE then blackhole formed
  • gravitational field so strong nothing escapes
    - not even light
18
Q

Why do orbits exists

A
  • Speed is balanced
  • with gravitational force (gravity)n
19
Q

What is a satellite

A
  • Something that orbits a celestial body
    • star
    • planet
    • moon
  • can be natural
    • moon or planets
  • or artificial
    - ISS 
    • GPS
20
Q

Describe a circular orbit

A
  • Constant speed
  • changing direction
  • so velocity is constantly changing
  • therefore accelerating towards centre of circle
  • acceleration = change in velocity/second
21
Q

What happens if an orbiting object speeds up

A
  • Move to higher orbit
  • If fast enough it will escape the gravitational pull and fly off to space
22
Q

What happens if an orbiting object slows down

A
  • fall into lower orbit
    • closer to earth
  • If too slow it will crash into earth
23
Q

What is the doppler effect

A
  • change in frequency and wavelength
  • because wavesource moves relative to an observer
    • moves closer to you and then further
24
Q

Dopper effect in stars

25
Explain red shift
- Spectrum of light from sun has absorbtion lines where hydrogen and helium (in the sun) have absorbed light - Light waves are streched out if a star or galaxy is moving away from an observer - wavelength increases - light (seen by the absorption spectrum lines shifting) is shifted towards red (longer) end of visible spectrum
26
Blue - shift
- If a star or galaxy is moving towards the observer - Light waves compress - wavelength becomes shorter - shifted to blue end of visible light spectrum
27
What is red-shift evidence for
- That galaxies are moving apart from eachother - the universe is expanding - the faster a star is moving away from the observer the greater the effect of red shift - the further away a galaxy is from observer the faster they move
28
What is the big bang theory
- 14 million years ago - universe was very small, extremely hot and dangerous region - there was an explosion and whole universe expanded outwards
29
What is evidence for the big band theory
- Red shift - At some point light must have had extremely short wavelength - everything moving apart suggests that everything came from a centralised region
30
CMBR --> Big Bang?
- Microwaves were discovered coming from every direction - Microwaves had been redshifted - must have been large energitic event - Cosmic Microwave Background Radiation
31
Other theories for origin of the universe
- Steady State - Universe has always existed - Universe is expanding - Constantly creating matter as universe expands - not supported by CMBR
32
What will happen to our universe
- Depends on total mass of universe - havent observed dark matter - Less dense = expand forever --> big yawn - stars will die out - universe will cool - more dense = stop expanding and collapse --> Big Crunch - scientist think universe has gone through cycles of this
33
Balloon model
- Draw marks on outside of balloon - when blown up marks move away from eachother - red-shift and expanding universe - easier to understand that galaxies don't move but space inbetween them does
34
Balloon Model inaccuracies
- No galaxies inside the balloon - could burst