our solar system Flashcards
1
Q
what is there in our solar system?
A
one sun, 8 planets, dwarf planets, natural & artificial satellites
2
Q
what is our solar system a part of?
A
the milky way galaxy
3
Q
artificial v natural satellite
A
artificial - satellites that humans have built e.g for weather, navigation
natural - e.g moons
4
Q
how was the sun formed?
A
from a cloud of dust and gas (nebula) pulled together by gravitational attraction
5
Q
what is a nebula?
A
a cloud of dust and gas
6
Q
how do nebulas form protostars?
A
the force of gravity pulls the dust and gas together
7
Q
how do the dust and gas drawn together cause fusion reactions? (protostar -> main sequence)
A
- as the protostar gets denser, the temperature rises and more particles collide with each other
- when the temp gets high enough, hydrogen nuclei undergo nuclear fusion to form helium nuclei
- this gives out huge amounts of energy which keeps the core of the star hot
8
Q
what do fusion reactions lead to and how? (main sequence)
A
- fusion reactions lead to an equilibrium between the
gravitational collapse of a star and the expansion of a star due to fusion energy - once the main sequence star is born after nuclear fusion, the star enters a stable period where the outward pressure caused by the nuclear fusion, trying to expand the star balances the force of gravity, pulling inwards
- this period typically lasts several billion years
