Is it a question about Chinese language? Yes,as far as I know,in Chinese there is a similar saying to Ver de terre amoureux à une étoile (蚯蚓爱繁星?qiu1 ying3 ai4 fan2 xing1,this expression doesn't exist in Chinese) that is 癞蛤蟆想吃天鹅肉.(lai4 ha2 ma2 xiang3 chi1 xian1 e2 rou4) It means someone reaches for what is beyond his/her grasp,especially refers to a relationship between two people.癞蛤蟆想吃天鹅肉, literally means a toad wants to eat swan meat,very idiomatic expression. You could also use: 痴心妄想 (chi1 xin1 wang4 xiang3) :aim at the moon/ask for the moon/cry for the moon P.S:but as you've noticed,there seemed to be something similar between different contexts.(Ground and the sky,ugliness and beauty,etc) :)

Ground worm in love with a star? Je pense que c'est une metaphore pur indiquer que quelq'un aime une personne trop loine et différente de lui, aussi loine et différente qu'une étoile d'un ver; je parie que ça pourrait bien être usé en genaral pour les amibitions et les rêves impossibles aussi. J'éspère que ça ira :) I think it's a metaphor refering to one in love with some too distant/different person (as a star to a worm); it probably may be used to define an ambition or a dream as impossible in genral. Hope this helps :)

can u use english? i dont understand it. sorry.