Gift for 16 year old Aspiring astrophysicist,,,,
there is a series of educational Japanese manga comics books called &quot;The Manga Guides&quot; they explain a particular subject of science and maths (like Physics, Relativity, Regression Analysis, Statistics, etc) and they are fun to read, I gifted the one on Physics to my 14-year old nephew and he liked it. Also the book has actual exercises between chapters and explained examples, and each book are independent, so you are not obligated to read all of them to finish the story.
https://en.wikipedia.org/wiki/The_Manga_Guides#The_Manga_Guide_to_Physics
There is one on the Universe and General Relativity too. I read the one on Relativity out of curiosity and it was very entertaining