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Space Physics - Coggle Diagram
Space Physics
Solar System
Contains one star
8 planets, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto
Planets orbit the sun
Dwarf Planets like Pluto which are too small to meet all the rule to be a planet
Natural satellites: Orbit planets, non man made
Artificial satellites: Man made, many orbit the earth
In the Milky Way Galaxy
Orbits
If an object is travelling in a circle, it is constantly changing direction
Constantly changing velocity
For an object to accelerate, there must be a force acting on it.
For circular motion, the force is directed toards the centre of the circle (centripetal force)
An orbit is the balance between the force providing the acceleration and the forward motion (instantaneous veolcity) of the object
The object keeps accelerating the what it's orbiting, but the instantaneous velocity keeps it travelling in a circle
Red-Shift
Light from Distant Galaxies wavelength's appear to have increased
They're shifted towards the red end of the EM spectrum
Occurs when light is moving away from the observer
Expansion of the Universe
Suggests that the galaxies are moving away from us
Most distant galaxies are moving away from us very quickly
More distant galaxies have a greater red shift than closer ones
This suggests that all galaxies are moving away from eachother
Means that he whole universe is expanding, so initially it must have formed from a single point
Big Bang Theory
Something must have caused galaxies to move further away from eachother
Initially, all matter in the universe occupied one small dense space
The it exploded, causing space to expand
Supported by red shift measurements
Life Cycle of a star
Formation of a star
Initially form from a cloud of dust called a nebula
Force of Gravity makes the gas and dust collect otgehter to form a protostar
Gravitational attraction causes the density of the protostar to increase as particles within the protostar collide with eachother more frequently which increases the pressure
When the temperature is high enough, nuclear fusion can start hydrogen nuclei begin to undergo nuclear fusion to form helium nuclei
Releases massive amounts of energy and keeps the core hot
Main Sequence stars
Once a star has formed, it immediately enters a long stable period
Energy relased by nuclear fusion provides an outward pressure that tries to expand the star
This balances the force of gravity, creating an equilibrium
This stable period is called a main sequence star
Lasts several billion years
Death of stars
Size of sun
Smaller stars expand to red giants
When it runs out of hydrogen, the surface cools
It will then become unstable and eject its outer layer leaving behind a dense solid core, a white dwarf
As the white dwarf cools down, it emits less enegry
When it no longer emits a significant amount of energy, it become a black dwarf
Much larger than the sun
Stars larger than the sun expand into red super giants when they run out of hydrogen
They form elements as heavy as iron
When they run out of elemens to fuse they form a supernova, forming elements heavier than iron and ejecting them into the universe
A neutron star is left behind, it could become a black hole
Satellites
Natural
Formed by natural processes
Planets
Moons
Artificial
Polar
Travel over the North nd South Poles
Orbit takes a few hours
Used for Military and weather purposes
Geostationary
object travels at the same speed as the earth's rotation.
Stays fixed above a certain part of the earth.
Used for communication and GPS
orbit takes 24 hours