Sararin samaniya ya kunshi manyan kungiyoyi na taurari waxanda ake kira galaxies. Da galaxia tarin taurari ne, ƙura, da iskar gas haɗuwa da nauyi.
Una galaxia tana dauke da miliyoyin taurari. Galaxies suna aiki a cikin sararin samaniya, kuma suna motsawa daga juna. Edwin Hubble ya nuna cewa duniya tana fadada. Duniya na cikin damin taurarin da ake kira Milky Way.
da taurari suna da siffofi masu ban mamaki kuma kusan. Ba mu san adadin damin taurari da ke cikin sararin samaniya ba, masana kimiyya suna ganin dole ne dubun-dubatar su kasance. Tabbas taurari suna da kyawawan sunaye, kamar Milky Way, ko Galaxia Andromeda, yayin da wasu kawai aka ƙidaya su, tare da dangantakar haruffa da adadi, kamar galaxy NGC 300.
https://www.youtube.com/watch?v=mJ47Uvf8c6E
da taurari suna ba da ra'ayi cewa an jefa su bazuwar zuwa sararin samaniya. Wasu sun ware, yayin da wasu taurari an haɗa su wuri ɗaya a cikin sararin samaniya.
Galaxies suna cikin har abada motsi, kuma wasu masana kimiyya suna tunanin cewa wasu damin taurari suna cin wasu. Misali, suna tunanin hakan galaxia Andromeda mamaye wani galaxy, wanda zai bayyana ta sau biyu tsakiya