P16 Space (paper 2) Flashcards
what is the structure of the solar system
sun
mercury
venus
earth
mars
jupiter
saturn
uranus
neptune
what is the name of our galaxy
the Milky Way
Is the milky way a spiral galaxy
yes
How are stars formed
huge clouds of dust and gas (nebulas) were attracted together through the fore of gravity. As GPE is lost, thermal energy is gained (protostar) until there is enough heat adn pressure for nuclear fusion to occur (main sequence star)
what is nuclear fusion
when two hydrogen atoms fuse together
what is a satelite
something which orbits a larger thing
what si teh equation for work done
force x distance
what happens to a satelite as it slows down
spirals closer to earth
what is a geostationary orbit
an orbit about the Earth where a satelite remains above a constant point on the Earth’s surface
what is a polar orbit
this is an orbit about the earth which goes over the North and South poles
what are the uses of polar orbits
- mapping
- spying
- weather
explain the life cycle of a large star
- nebula
- protostar
- main sequence star
- red SUPERgiant
- supernova
- neutron star / black hole
what is the life cycle of a small star
- nebula
- protostar (star starting to heat up)
- main sequence star
- red giant [bigger, redder, brighter, cooler]
- white dwarf [smaller, dimmer, whiter, hotter]
- black dwarf
what forces make a star stable
- gravity
- radiation pressure
describe how the light elements are formed
- from fusion ( H -> He) in main sequence stars
- heavier elements are formed in red giant and red supergiants (up to iron)
how are all the elements distributed throughout the universe
scattered by supernovas
how are heavy elements formed
(elements heavier than iron) are formed in supernovas
describe some similarities and differences between planets, moons and artificial satellites
- planets and moos are natural satellites
- artificial satellites are man made
- all of these orbit a larger body
explain how planets and satellites move in a circular path
- circular orbits are caused by a cantripetal force
- gravity is the centripetal force
- satellitghts must be going at the right speed for a circular motion to occur
why do planets have a constant speed but have a changing velocity
velocity is a vector, it has size (magnitude) and direction.
whilst the size of the velocity does not change the direction of the planet is constantly changing
what is red shift
where galaxies are moving away from us - we see the wavelength increase and the frequency of the light decrease
what si teh relationship between the distance to a galaxy and its speed
the greater the distance this galaxy is away from us - the greater it’s recessional speed
explain the big bang theory
the idea that the universe started from a very small point and expaneded rapidly / exploded
explain how red shift has given evidence for the big bang theory
- if the universe is currently expanding in all directions, it must have come from a single point
- CMBR can only be explained by the big bang theory [we can’t explain how there is microwaves everywhere]
what does CMBR stand for
cosmic microwave background radiation
what is dark energy
the energy causing the universe’s expansion to accelerate
describe dark matter
the matter causing spiral galaxies to rotate faster than they should be
what is the densest object in the universe
a black hole
what do black holes do
they can warp time & space
what is the doppler effect
when there is relative motion between a source of sound and a reciever
what is blue shift
when objects are moving towards you - the wavelength decreases and the frequency of light increases
what does the colour of light depend on
the wavelength
which colour has the shortest wavelength
violet light
which colour has the longest wavelength
red light
what are the two types of satellites
- polar
- geostational
what are the three results of the universe
- open universe (continued expansion)
- flat universe (expansion but slowing)
- closed universe (universe will contract again)
how does CMBR support the big bang theory
because there is electromagnetic radiation everywhere, that can only be explained by the big bang theory - the radiation is left over from the big bang and has been red shifted into the microwave region.
expalin blue shift in terms of wavelength and frequency
- the wavelength decreases
- the frequency increases
What is cosmic microwave background radiation
Something which can only be explained with the Big Bang theory. It is the electromagnetic radiation left over from the Big Bang that has been red shifted into the microwave region.
