The Question and Answer section for The Curious Incident of the Dog in the Night-time is a great resource to ask questions, find answers, and discuss the novel.
Christopher's interest and description of the night sky are born in his desire to be far from the earth.
Check out 'Autism, language and communication' on the GradeSaver themes link. It's what you are looking for,
There are a total of forty-three letters written to Christopher by his mother. From this, we can infer that not only is Christopher's mother alive and well, she also tried to keep in contact with him.
I counted the letters. There were 43 of them....