Space - paper 2 Flashcards
To revise space (Paper 2)
Describe our solar system
the Sun, plus the eight planets and the dwarf planets that orbit around the Sun. Natural satellites, the moons that orbit planets, are also part of the solar system.
State the name of our galaxy
The milky way
How was the sun formed
The Sun was formed from a cloud of dust and gas (nebula) pulled together by gravitational attraction. This cloud heats up until fusion can start.
What reaction takes places in all stars
Nuclear fusion
Why are stars stable?
usion reactions lead to an equilibrium between the gravitational collapse of a star and the expansion of a star due to fusion energy.
Describe the life cycle of a small star, like the sun
Nebula Protostar Main sequence star Red Giant White dwarf Back dwarf
Describe the life cycle of a large star
Nebula Protostar Main sequence star Red Super Giant Supernova Neutron star or Black hole
Which was the first element created by the big bang
Hydrogen nuclei (protons)
How were the light elements made
Fusion in stars
How were the heavy elements made
Fusion in supernovas
How were all the elements distributed through the universe
By supernovas
What forces keeps planets in orbit around a star
Gravity
What is a stable orbit?
A stable orbit is one in which the satellite’s speed is just right - it will not fly off into space (too fast) or spiral into the Earth (too slow) but will travel around a fixed path.
What is the relationship between orbit radius and speed.
The gravitational attraction between two objects decreases with distance. This means that the closer the two objects are to each other, the stronger the force of gravity between them.
This means that objects in small orbits travel faster than objects in large orbits. In order to change orbital speed, an object must change the radius of its orbit at the same time, to maintain a stable orbit.
Define red shift
There is an observed increase in the wavelength of light from most distant galaxies. The further away the galaxies, the faster they are moving and the bigger the observed increase in wavelength.
