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Name the planets in order from the sun.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
Where would you find the asteroid belt?
Between the orbits of Mars and Jupiter.
Why is Pluto classed as a dwarf planet?
It’s small and has an orbit out of line with the other planets.
What is the ‘Goldilocks Zone’?
The region in the solar system where the temperature is not too hot and not too cold. This is where life is more likely to exist.
What is the Astronomical Unit (AU)?
The distance between the Earth and the Sun.
What is a light year?
The distance light travels in a year.
What is the definition of a planet?
An object that orbits a star.
What is the definition of a moon?
An object that orbits a planet.
What is a ‘Nebula’?
A cloud of gas and dust that is the beginning of solar system.
What is a protostar?
A star that is not hot enough for nuclear fusion to occur.
How does a star make energy?
Nuclear fusion reactions (lighter elements fuse together to make heavier elements).
What are the two forces that act on a star?
gravity and radiation pressure.
When the star is in the main sequence, what can you say about the two forces acting on it?
That they are balanced.
What are the stages in life of an average mass star?
Protostar, main sequence, red giant, white dwarf, black dwarf.
What are the stages in life of a massive star?
Protostar, main sequence, red supergiant, supernova, neutron star or black hole.
What happens to a star to cause the end of the main sequence?
It runs out of hydrogen.
How do heavy elements appear in our Universe?
They are formed inside a supernova and ejected into space.
What is the Hertzsprung-Russell diagram?
x axis = surface temperature
y axis = luminosity
What colour are the hottest stars?
Blue.
What colour are the coldest stars?
Red.
Where on a Hertzsprung-Russell diagram would you find the red giants and red supergiants?
Top right. (Cool and Bright).
Where on a Hertzsprung-Russell diagram would you find the white dwarfs?
Bottom left. (Hot and Dim).
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