SP7 space Flashcards
How does weight change in different bodies in space
it can increase or decrease depending on the gravitational field strength
what are natural satellites
natural space bodies which move around planets such as the moon to the earth
what are dwarf planet
space bodies similar to planets but arent big enough such as pluto
what is our solar system made up of?
the sun at the centre
8 planets that orbit the sun - mercury, Venus, earth, mars, Jupiter, Saturn, Uranus, Neptune
and has natural satellites like the moon
there are also asteroids and dwarf planets
explain the geocentric model
it was the first inital model
- suggests the earth is at the centre and the sun orbited the earth
-everything orbited in perfect circles
explain the heliocentric model
the modern one
- the sun is at the centre
- the orbits are in an eliptical shape, oval shape
proven by:
Galileo who observed that moon orbited Jupiter so not everything orbited the earth
the earth spinning faster than mars so overtakes it and appears its reverse direction in the sky
what happens as planet orbit the sun
the gravitational force causes the planets to constantly change direction around the sun
but the speed stays the same, so velocity is always changing
what happens if a planet moves closer to the sun
- the orbital radius will decrease
-the gravitational attraction to the sun increases
-so the orbital speed of the planet increases
what is the big bang theory
a concentrated energy 13.5 billion years ago expanded from this point and is still expanding
evidence for the big bang theory
CMB- cosmic background radiation
-when the universe was young there would be alot of short wavelength radiation emitted.
as the universe expands over time, the short wavelenth radiation will become stretched into microwaves
- this background radiation is present when pointing a teloscope in the sky
- this proves that the universe had cooled and expanded
the steady state theory
supported by the red shift
- matter is being constantly created and so there is constant density in the universe
- this suggests that the universe was always there and is expanding and new matter is being created as the universe expands
how are regular stars made?
nebula/cloud of gas
pulled together by gravity and heated, the gravitational pull gets stronger as the cloud becomes more dense
protostar
eventually the pressure and temperatures in the centre of the star will become high enough for fusion reaction to occur to release electromagnetic radiation and form
main sequence star (the sun rn)
after a lot of fusion reaction the core is not hot enough and collapses, causing the outer layers to expand into a
red giant
the red giant will throw off a shell off a shell of gas and the rest of the red giant will be pulled by gravity and collapse into a white dwarf.
life cycle of a massive star
a considerable more mass than the sun are hotter and brighter
cloud of gas
more gravity and material being heated
protostar
the temp inside the centre will be hot enough to form a
massive main sequence star
they fuse with hydrogen and helium faster to become
red super giants
at the end of the red super giant the star will rapidly collapse and form a supernova
gravity will pull the rest of the mass left behind together to form a black hole
if the remains are not big enough to form a black hole gravity will form a neutron star
