• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

Card Range To Study



Play button


Play button




Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

38 Cards in this Set

  • Front
  • Back
Name 3 other things that orbit the sun
Dwarf planets
Name difference between stars and planets
Stars - huge, very hot and far away, give out light
Planets - smaller, much closer and reflect sunlight
When did the solar system form?
5,000 million years ago
How did the solar system form?
A cloud started to squeeze and it's particles got closer to one another and then gravity locked in and pulled in everything so close that it collapsed on itself
At the centre the particles formed a protostar that got so hot that nuclear fusion began and it became the sun
What are comets made of?
Rock dust and ice
How many stars are there?
Thousands of millions
How many galaxies are there in the universe?
Thousand of millions
What is a light year?
The distance that light travels through a vacuum in a year
What is the speed of light?
300 000 km/s
How old is the earth, sun and universe?
Earth - 5000 million years
Sun - 5000 million years
Universe - 14 000 million years old
Name the two factors that can help us identify how far away a star is
What is parallax?
When something appears to move when you look at it from different places
Astronomers take pictures of the sky six months apart - the bigger the movement the closer it is
What is red shift?
When the wavelength of light changes as a galaxy is moving away - the redder it is the quicker it's moving away
Evidence that the universe is expanding
Redshift shows the more distant the galaxy the further it moves away from us
Why does the universe expand?
The matter and energy of the universe was compressed in a small space and then it exploded and started expanding
How may the universe end
If there enough mass the universe will stop expanding and begin contracting - the Big Crunch
If there's not enough mass it could expand forever
Evidence of a changing earth?
Rocks are eroded yet made again by lava from volcanoes.
Fossils deep in rock
What happens in the rock cycle?
Particles erode from existing rock
Washed into the sea and settle as sediment
Crushed together to make sedentary rocks
Can be pushed to the surface or pushed down into heat and pressure
Eventually rise to the surface and are eroded again
What was Wegners theory?
There had been a supercontinent called Pangaea which broke due to continental drift - explained why the coastlines fit and matching layers of rocks and similar fossils
Why was Wegner's Theory not accepted?
He was a meteorologist
Couldn't explain how the drifting happened
Movement wasn't detectable
What is the structure of the earth?
Crust (oceanic and continental)
Liquid outer core
Solid inner core (nickel and iron)
Volcanoes and mountains form at
Plate boundaries
Mountains are formed by
Plates crashing into one another
How are the Himalayas formed?
India is crashing into the Eurasian plate
You record seismic waves with
When there's an earthquake, wave motions are produced which travel on the surface and inside the earth, seismologists measure...
The time it takes the shock waves to reach each seismograph
Which parts don't receive the shock waves
What are the two seismic waves?
P waves (longitudinal waves)
S waves (transverse waves)
Properties of P-waves
Travel through solid and LIQUID
Faster than S waves
Properties of S-waves
Travel through solids only
Slower than p-waves
How do seismic waves show the structure of earth
P-waves change direction halfway through - sudden change in properties from mantle to core
S-waves not detected in core - outer core is liquid
P-waves travel quicker through inner core - it's solid
What is a wave
A disturbance caused by a vibrating source which transfer energy
What is the amplitude?
The distance from the rest position the the crest or trough- shows the amount of energy
What is the wave length
The length of a full cycle of the wave
What is frequency
The number of waves passing a certain point per second
Distance =
Speed x time
What are transverse waves? (E.g EM waves)
Waves where the vibrations are at 90 degree to the direction of travel of the wave
What are longitudinal waves?(e.g sound)
Waves where vibrations are along the same direction as the wave is travelling
Wave speed(m/s) =
Frequency (Hz) x wavelength (m)