What is the order of the planets from the sun?
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
What is a moon?
A natural satellite that orbits a planet
What is a protostar?
Where nuclear fusion begins to form a star, hydrogen atoms fuse to form helium
Describe the life cycle of a star like our sun
- Cloud of dust forms called a nebula
- Then it becomes a protostar, and nuclear fusion begins
- Nuclear fusion leads to it being a main sequence star
- Nuclear fusion goes on until it becomes a red giant
- When fusion stops, the star will become a white dwarf
Describe the life cycle of a massive star
- Cloud of dust forms called a nebula
- Then it becomes a protostar, and nuclear fusion begins
- Nuclear fusion leads to it being a main sequence star
- Nuclear fusion goes on until it expands to become a red super giant
- When nuclear fusion stops a supernova will happen
- It will then become a neutron star or a black hole
What is an asteroid?
A small object composed of metal and rock that follows an elliptical orbit around its sun
What is a comet?
A small object composed of rock, dust and ice that follows an elliptical orbit around its sun
Other than what it’s made up of, what is different between a comet and an asteroid?
Comets begin to vaporise as they approach a star, turning it into gas which forms a distinctive tail
Describe the relationship between the weight of an object and the gravitational field strength
They are directly proportional
Describe the speed and velocity for things that follow circular orbits
The speed stays the same but the velocity changes due to gravity
How does the balance of thermal expansion and gravity affect the lifecycle of stars?
- Smaller stars have longer lives due to smaller forces of gravity, that are easier to balance
- Larger stars have shorter lives due to larger forces of gravity, that are more difficult to balance
Why is the gravitational field strength different for other bodies in space?
They have different masses
Why is a person’s weight different on a different planet?
Because the gravitational field strength is different
W = mg
What is a dwarf planet?
A body is space unable to clear its neighbourhood (meaning other things could be in the same orbit)
How have ideas about the structure of the solar system changed over time?
For a long time people believed in the geocentric model, with Earth in the centre and The Sun and planets orbiting around it
Do satellites in a circular orbit maintain a constant speed?
Yes
Do satellites in a circular orbit maintain a constant velocity?
No, due to changing direction
What do planets orbit?
A barycentre, the common centre of mass of itself and the star
What type of orbit does a planet follow?
Circular
What type of orbit does a moon follow?
Circular
What type of orbit does a comet follow?
Elliptical
What type of orbit do artificial satellites follow?
Circular
What happens if the speed of a satellite increases in a stable orbit?
The radius of the orbit will increase
What is redshift?
The increase in wavelength of light from objects moving away from Earth
