I haven’t yet seen the new Luc Besson film, Valerian and the City of a Thousand Planets, but I have read a number of the French comics (bandes dessinées) on which the movie was based — Valérian and Laureline (alternately, Valerian: Spatio-Temporal Agent), created by writer Pierre Christin and artist Jean-Claude Mézières.
Mézières is an influential and highly respected French comics artist, though not well known here in the U.S. except among fans of Franco-Belgian comics.
He has worked on a number of comics and illustration projects over the course of his career, but is best known for his work on Valérian and Laureline, and as a concept designer for films like Luc Besson’s The Fifth Element (including the designs that inspired the flying taxis).
Valérian and Laureline is a long running science fiction comics series that was originally serialized in the French comics magazine Pilote. It has been tremendously influential on both comics and film.
It’s widely recognized to have been a distinct but uncredited influence on George Lucas in his designs and settings for the original Star Wars trilogy. There is an article on Core 77 that points out some of the parallels between scenes from the movies and prior comic panels from Valérian and Laureline. There is another article pointing out what Star Wars took from Valérian and Laureline on Popular Mechanics.
Mézières’s style is more light and cartoony than the styles usually associated with American super-hero and adventure comics, but it gives the stories and the characters a jaunty, breezy character, and works well with Mézières’s wildly imaginative settings.
The French Valérian and Laureline comics albums have been translated into English, and most recently are being collected into a series of volumes with three of the original French albums (what might be called “graphic novels” here) in each volume. There are three collected volumes available as of this writing.
You could start with Valerian: The Complete Collection, Volume 1 (Amazon link), and go from there to Valerian: The Complete Collection, Volume 2, or if you want to get right to the stories on which the film is most directly based (and that are the most overt space opera), start with Valerian: The Complete Collection), Volume 3. Beyond that, there are older printings of individual albums.
There is an official website for Jean-Claude Mézières, but it’s in French and does not feature as many images as one might hope. It is useful, however, for it’s listing of the Valerian albums (titled as Valerian, sptio-temporal agent).
The best resource I can find for Mézières’ art is this article from 2015 on Dark Roasted Blend.
You can also find some originals on Comic Art Fans.
If you try a Google image search for “Valerian”, it will mostly come up with promo pictures for the movie; try searching for “Valerian comics”, “Valerian and Laureline”, “Valerian et Laureline” or ‘Jean-Claude Mézières”.