The universe

W h a t    i s    t h e    u n i v e r s e    ?

The universe is the matter , energy and space that exist . It includes everything from the crumbs on your kitchen floor to the sun , the planets , all the stars and galaxies , the dust and gas between the stars , and the light that travels  through the space together . The  word "universe" comes from Latin phrase meaning "turning as one" . 
Although it is hard to tell from where we stand , the universe has a structure .Planet orbit stars . Stars billion of them , clump together in the galaxies . There are about 100 billion altogether in the universe . Most galaxies are found from the group called cluster . Cluster , in turn , usually from even larger groups , called super-clusters . Finally super-clusters cling to another in  even more enormous structure that look like walls or sheet of galaxies . These unimaginable huge groupings are the largest features of the universe . 

F a s t     F a c t s

T h e    s c a l e    o f    t h e    u n i v e r s e 

Earth                                                    12,756 km across.


Sun                                                       1,392,000 km across.


Earth's orbit                                           About 300 million km across.


Pluto's orbit                                          About 12 billion km across.


Milky way galaxy                                 100,000 light years across


Local group                                          6 million light years across


Local super-cluster                               80 million light years across


Observable universe                              26 to 30 billion light years across