To Melt
To Dissolve, To Thaw
intransitive verb, ichidan verb
溶かす is "to melt something" and that makes 溶ける to melt (where something just melts, and you're not doing the melting).
The reading comes from 溶かす.
あの光り輝く星々が、夜空に溶けるのを想像してみてください。
Imagine that the glittering stars are all melting into the night sky.