Patricia holds Natasha's hand as the plane takes off, comforting her. Natasha looks at the stars, thinking that they're more than poetic—you can navigate using them.
When Natasha thinks of poetry first and then sets poetry alongside science, it shows again how Daniel helped her recognize the role of art.
Daniel ignores phone calls from his parents and thinks that maybe he won't go to college. He looks up and imagines Natasha's plane, and he thinks that the city has too much light pollution to allow someone to ever see the sky. However, he knows that the night sky gives off light, even if he can't see it.
Understanding that the sky is light even though he can't see it represents the cosmic interconnectedness of all people. Essentially, Daniel knows that Natasha is there and has feelings for him, even if they can't see each other.