A simile is a figure of speech that directly compares two things through some connective, usually like, as, than, or a verb such as resembles.. A simile differs from a metaphor in that the latter compares two unlike things by saying that the one thing is the other thing.
A galaxy is an enormous collection of gas, dust and billions of stars held together by gravity. One galaxy can have hundreds of billions of stars and be as large as 200,000 light years across.
[Source] A map of the galaxy showing the locations of various planets. The galaxy, as it was commonly referred to, was one of the many galaxies in the universe. Composed of a collection of stars, planets, other astronomical objects, it was originally formed by a supermassive black hole in its center.