space physics Flashcards
what galaxy is our solar system part off
the Milky Way galaxy
how many planets do our solar system make up
8
what do the plants in our system orbit around
the sun
what type of body is the sun
a star
what type of force pulled together the cloud of dust and gas to form the sun
gravitational force of attraction
what word is used to describe a cloud of dust and gas
a nebula
what type of reactions take place at the start of a star lives cycle as dust and gas is drawn together
fusion reactions
what factor determines the type of lifecycle of a star undergoes
the size of the star
which two phases do all stars of the same or greater size than the sun undergo
- protostar phase
- main sequence phase
what do stars of a similar magnitude to the sun become at the end of their life-cycle
a black dwarf
what two things can stars much bigger than the sun become at the end of their lifecycle
- neutron star
- black hole
what 2 phases do stars of a similar size to the sun go through between being a main sequence star and a black dwarf
- red giant
- white dwarf
what 2 phases do stars of a greater size than the sun go through between being a main sequence star and a neutron star/black hole
- red super giant
- supernova
what are produced during the fusion processes in a star
all of the naturally occurring elements
what condition is required for fusion reactions to occur in a star
very high temps
how are elements heavier than iron produced
supernova
what type of nuclei fuse together to form heavier elements in a star
hydrogen nuclei fuse to form heavier elements
how are elements distributed throughout the universe
through the explosion of a massive star
supernova
how are elements distributed throughout the universe
through the explosion of a massive star
what allows planets and satellites to maintain circular orbits
gravity provides the gravitational force that acts as the objects centripetal force
the presence of a centripetal force allows for the object to maintain its circular orbit
what type of satellite can a plants moon be described as
a natural satellite
give 2 examples of artificial satellites
- tv satellites
- satellites used for satellite images
explain why for a stable orbit, the radius of orbit must be change if the speed changes
at higher speeds, the object requires a greater centripetal force
for greater centripetal force, the gradational force must increase
this is achieve by the radius of the orbit being reduced
explain how the force of gravity acting on a satellite affects its speed and velocity
the force can alter its velocity since the direction is continually changing
it cants cause a change of speed since there is no force component in the direction of motion
what is red-shift
an observed increase in the wavelength of light from distant galaxies
what two things can be said about the motion and wavelength of emitted light from a galaxy, the further away it is
the further away a galaxy is, the faster it is moving
the further away a galaxy is, the greater the observed increase in wavelength
what does red-shift provide evidence for
provides evidence that the universe is expanding
supports the Big Bang theory
what does the Big Bang theory suggest
the entire universe started from a very small, hot and dense region in space
compare the observed red-shift of two galaxies, one further away than the other
the galaxy that is further away is travelling faster
the observed red-shift is greater the fitter away it is
what did scientists observe to prove evidence that the universe is expanding at an ever faster rate
they observe supernovae which suggested that galaxies are moving away at an ever faster rate
prior to observations of supernovae what was believed about the rate of expansion of the universe
the rate of expansion was expected to occur at an ever slower rate
it was thought that gravitational forces would cause this slowing down
wat 2 ideas could explain the universes ever increasing rate of expansion
the existence of energy and mass that we cannot detect - known as dark matter and dark energy
these ideas are still be developed by scientists and are not yet fully understood
