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It was a novel and the non-human nature of the protagonist and their species is revealed only gradually. They're some kind of animate and mobile plant species that reproduces by budding. They're 'trapped' on their planet and a handful are frantically attempting to develop space travel before a recurring catastrophe destroys their civilisation.
The catastrophe was probably an asteroid field or meteor swarm that their planet passed through at regular intervals, a main character was an astronomer who realised that the planet moved deeper into the debris with each cycle and that the next cycle or two would become too severe for their species to survive.
Update: I couldn't say how old the book is but probably written before 1990, it could be as old as golden age scifi but maybe it felt a bit like a 1960s era novel.
I read it over a decade ago, possibly in the '80s. There are no humans in the story, the story is entirely devoted to the plant-like species who are the dominant race on their world. They do eventually escape, or some of them do at any rate. I don't recall the end but I don't think they come to Earth.