Steve Foxe 
Mr Kazarian, Alien Librarian [PDF ebook] 

All of the children love Mr Kazarian the librarian. He makes learning fun, and his library is their favourite place to hang out. What they don’t know is that Mr K is actually an alien, sent to Earth to study the habits of these bizarre creatures called humans. When four of his pupils discover his human hologram disguise, Mr K’s research is in jeopardy … unless a trip to space will persuade them to keep his secret? A science-fiction graphic adventure with lots of actual science!