Space Physics Flashcards
What galaxy is out solar system part of?
The milky way galaxy
How many plants make up our solar system?
Eight
What do the planets in our solar system orbit around and what type of body is it?
-Planets orbit around the sun
-The sun is 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 factor determines the type of lifecycle a star undergoes
The size of the star
What happens when protostars increase?
- More and more particles join
- Increases in size
- Force in gravity gets stronger
- So more dust and gas is pulled in
- Increases density, so particles collide more often
- Raising temp of protostar
- Nuclear fusion
Life cycle of smaller stars
Nebula - Protostar - Main sequence star - Red giant - White dwarf- Black dwarf
Why do main sequence stars have a long stable period
- Outwards pressure caused by nuclear fusion is equal to the inward pressure of gravity
How are elements other than hydrogen created by main sequence stars
- Eventually it begins to runs out of hydrogen
- Less nuclear fusion
- Inwards pressure is greater so it compresses the star
- Which increases the density so nuclear fusion occurs again
- It expands again and forms heavier elements (up to iron)
Life cycle of larger stars
Nebula - protostar - main sequence star - red super giant - Supernova -
How is a white dwarf formed
- Red giant becomes unstable to expels its outer layers
- Leaving a hot, dense, solid core where no nuclear fusion occurs
How is a black dwarf formed
- When a white dwarf emits all of its energy
- No longer has enough energy to emit light
How are elements heavier than iron produced
- Red super giants go through lots of nuclear fusion
- Eventually explode in a supernova
What type of nuclei fuse together to form heavier elements in a star?
Hydrogen nuclei fuse to form heavier elements
What allows planets and satellites to maintain circular orbits
- Gravity provides the gravitational force that acts as the object’s centripetal force
- The presence of a centripetal force allows for the object to maintain its circular orbit
Explain why for a stable orbit, the radius f orbit must change if the speed changes
- At higher speeds, the object requires a greater centripetal force
- For a greater centripetal force, the gravitational force must increase
- This is achieved 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 cant 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 its moving
- The further away a galaxy is, the greater the observed increase in wavelength
what does red shift provide evidence for
- Evidence that the universe is expanding
- Supports the big bang theory
What does the big bang theory suggest
The entire universe started from a singular very small, hot and dense region
Compare the observed red-shift of two galaxies, one further away than the other
- The one further away is travelling faster
- The red shift is greater the further away it is
What did scientists observe to provide evidence that the universe is expanding at an ever faster rate
They observed supernovae, which suggested that galaxies are moving away at an ever faster rate
