I wish I could say that I liked this more. It's very good, and it's a quiet, character-driven story, but I wanted more from it. 
 I wanted to see more of Jack, who is discovering an interest in astronomy because he's interested in the girl, Ally, who is lecturing about it. I want to know more about why he didn't pay attention in class and got sent to summer school, and what it was that his teacher saw in him to invite him on the eclipse trip. 
 Ally is super-interested in astronomy and has been preparing for this solar eclipse nearly her whole life. I think we saw enough of her--she's growing up and she's unsure of herself socially, as her friend is growing up and away from her this summer. 
 Bree is super-vain and super-unexcited to be moving to this campground in the middle of nowhere. She's got some interests that she's pushed down, and I want to know more about them. Why is she drawn to help when a child has an allergic reaction? What made her turn off all her interest in her parents' scientific research? 
 The way these three become friends makes sense and doesn't feel forced. I'm not sure what will become of them after the book closes, but I want to know more about where they were before I opened the cover.