space - the solar system Flashcards
what is our solar system
sun, mercury, Venus, earth, mars , Jupiter, Saturn, Uranus, Neptune
what is at the centre, what is it
the sun which is a big star
what is found beyond the orbit of Neptune and give an example
dwarf planets - e.g. pluto
what other objects are found in our solar system
moons, asteroids, comets
what are moons
natural satellites which orbit planets
our solar system is a small part of a big galaxy, what is its name
the milky way galaxy
what is a galaxy
a massive group of stars
how do stars form
from clouds of dust and gas
what are clouds of dust and gas called
a nebula
what gas is mainly in a nebula
hydrogen
what happens in the first stage
gravity causes the cloud of gas to collapse
what is this called
a proto star
what happens if the temperature od the protostar increases
if it gets high enough then hydrogen nuclei joints together to become helium
what is this process called
nuclear fusion
what makes the star collapse
gravity
what make the star expand
force from nuclear fusion
why do scientists say a star is in equilibrium
because gravity which is the inward fore = the force created from nuclear fusion which is the outward force
