Space Flashcards
What is the universe made up of?
Billions of galaxies.
What does each galaxy contain?
It contains hundred of millions of stars.
What is the solar system made up of?
It is made up of:
one star- the sun
planets and dwarf planets that orbit the sun
asteroids and comets that also orbit the sun
moons that orbit planets–natural satellites.
What is a nebula?
Cloud of dust and gas which was pulled together by gravitational attraction.
How are protostars created?
As the dust and gas were drawn together, they collided, increasing the temperature and creating a protostar and then eventually a main sequence star.
How is a main sequence star created?
Material is drawn by gravity these collisions increase until the temperature and pressure is high enough for hydrogen nuclei to fuse together forming helium and a main sequence star.
What happens to the material that is not drawn into the sun?
It remains in the orbit and forms the planets and other objects in our solar system.
What does the sun’s stability result in?
The stability is the result of the balance between :
The fusion energy trying to expand the sun
gravity acting inwards trying to collapse the sun.
How do the different sizes of stars end up?
Small stars (eg the sun) - end up as black dwarf stars.
Larger stars become neutron stars
The largest stars become black holes.
How do stars begin?
Clouds of dust and gas are drawn together by gravity to form a protostar and eventually a main sequence star.
What happens during a main sequence star?
Hydrogen fuses together to create helium and in large stars lithium.
What happens as the star ages?
1) Mass transforms into energy through nuclear fusion.
2)As mass decreases the outwards force becomes larger than the force from gravity.
3) The star expands then cools becoming a red giant or a red super giant.
4) As the star cools and the hydrogen fuel is used up the outward forces are reduced.
5) Star collapses inward due to gravity causes increase in temperature.
6) It begins to fuse helium and lithium.
What does the largest star become?
A supernova- releases energy and scatters material of the star into space.
How are new elements formed?
They are formed in stars by nuclear fusion.
What does the planet orbit and what does the
moon orbit?
The planets orbit the sun.
The moons orbit a planet.
How do objects, planets and satellites travel in a circular path? What does this result in?
For an object, there must be a force that acts towards the centre of the circle.
For planets and satellites, it is the force of gravity that acts toward the centre.
This results in an acceleration towards the centre.
What happens to an object undergoing circular motion?
- The acceleration does not cause the object to change speed.
- The acceleration causes the object to change direction.
- The velocity changes but the speed remains the same.
- The instantaneous (occurring) velocity is perpendicular to the centripetal (force that acts on an object to keep it moving along a circular path) force.
How do you stay in a stable orbit?
To stay in a stable orbit, at a particular distance from a large body, the smaller body must move at a particular speed.
