space Flashcards
what is the life cycle of all stars up to the changing point
5 points
1.clouds of dust and gas (nebula)
2.nebula->protostar due to gravity
3.protostar gets bigger as gravity is stronger
4.protostar->main sequence star, as outward pressure(fusion)=inward pressure(gravity)
5.main sequence star runs out of hydrogen- it fuses helium into heavier elements
what causes protostar to change into main sequence star
4 points
-gravity gets stronger=protostar gets denser
-particles collide more often
-raises temp and pressure
-causes nuclear fusion
life cycle of star bigger than sun
4 points
1.main sequence star runs out of hydrogen-
2.main sequence star->red supergiant
3.red supergiant->supernova due to explosion
4.supernova can condense->neutron star
supernova can collapse->black hole
life cycle of star smaller than sun
4 points
1.main sequence star runs out of hydrogen
2.main sequence star->red giant
3. red giant->white dwarf as it becomes unstable
4.white dwarf->black dwarf as it gets cooler and darker. there’s no more energy to emit light
what are circular orbits
3 points
earth’s orbit is virtually circular
moon is a natural satellite
-gravity acting between sun and earth/moon holds the earth in its orbit
-force of gravity leads to a change in velocity, not speed
what happens if the speed of a satellite changes
-radius of orbit changes
-speed increases=radius decreases
what happens to satellites at higher speeds
2points
-it needs a greater force of gravity to prevent it flying off into space
-by moving closer to earth, gravitational force of satellite is greater and it remains in stable orbit
what is red shift
2 points
-lines on spectrum shift towards red end
-shows galaxies are moving away from each other and the observed wavelength is increased
explain red shift and big bang
2 points
-distant galaxies moving faster than nearby galaxies provides evidence that the universe is expanding
-universe began as a very small, hot dense region and expanded into current universe
