Topic 7 Astronomy(completed) Flashcards
What is the order of the 8 planets from the sun
Mercury
Venus
Earth (Inner Outer rock Planets)
Mars
(Asteroid belt)
Jupiter
Saturn
Uranus (Gas giants)
Neptune
(Pluto Dwarf planet)
What is the dwarf planets in our solar system called
Pluto (too small to be called an actual planet)
What is a natural satellite
Things like the moon not man made and they orbit planets with almost circular orbits
What are artificial satellites
Artificial Satellites are man made and orbit the earth usually in circular orbits
What are asteroids and comets
Asteroids-lumps of rock and metal that are usually found in the asteroid belt and orbit sun
Comets-lumps of ice and dust and orbits are highly elliptical (very curved circle)
What is g
G means gravitational field strength
Other bodies in space (such as the moon)may have different gravitational field strengths so objects will vary in weight
Weight = Mass >< gfs
N. Kg. N/kg
What did the geocentric model about space suggest
That all bodies in space orbited the earth
What did the heliocentric model suggest
Said that all bodies in space orbited sun in perfect circles
What does current model suggest
All planets orbit sun but in elliptical orbits and sun isn’t the centre of the universe
When planets orbit the sun the velocity always changes as the direction always changes but the speed stays the same
What does the steady state theory say
Universe always existed
Universe expands and new matter is always being created
No beginning or end to universe
What does the Big Bang theory say
Universe started with an explosion that was very dense and hot
Space is expanding
What is red shift
Theory that galaxies are moving further away from earth and further galaxies are moving faster than nearer ones
Explain how red shift works
-Different elements absorb different frequencies of visible light shown by black lines
-Lower frequencies means something is further away
The black line readings have been moving to lower frequencies over time so means galaxies are moving away from earth
What is Cosmic Micro Background Radiation
Low frequencies of microwave radiation in space from the initial explosion that started the universe
What models does red shift support
Red shift solid ports both the Big Bang and steady state theory
Both models suggest objects are moving away from earth
What models does the CMB support
CMB radiation only supports Big Bang theory as it shows the universe had a beginning unlike the steady state theory
CMB and red shift both support Big Bang theory so that is why it is the currently accepted theory
What happens to the sound waves of a moving object (frequency)
The sound waves decrease in frequency(lower pitch) further away and have higher frequency(higher pitch) closer up
Stars initially form from a cloud of dust and gas called what?
A nebula
Gravity pulls gas and dust together inwards to from ______
Protostar
What process happens in the protostar
Nuclear fusion
Gives out lots of energy which creates star
What 2 forces balance out in the main sequence star(lasts for billions of years)
Thermal expansion outwards
Gravity inwards
