Galaxies are big bunches of stars . They are usually observed in big groups called clusters . Our galaxy is called the Milky Way . Scientists believe that there are 100 thousand million stars in the Milky Way .
From Earth , galaxies seem like small shiny bright swirls and streaks , but if you look within space , you will see a big difference . People have explored a lot of galaxies , but there are still a lot of galaxies to observe among us .