Disney's critically-lambasted film John Carter is an adaptation of Edgar Rice Burroughs' much adored sci-fi novel A Princess of Mars.

No, I’m not suggesting a spin-off in which John Carter from the recent movie of the same name fights off an evil princess from Mars.  It’s much simpler than that—I’m comparing John Carter the movie with A Princess of Mars, the book that inspired it.

Both stories focus on John Carter and his adventures on the Red Planet. In the book by Edgar Rice Burroughs (1875-1950), Carter’s a Confederate general loaded with Confederate money he can no longer spend, which drives him to mine for gold. While hiding out in a a cave in Arizona, Carter is mysteriously teleported to Barsoom (Mars). The movie starts out similarly, but from there the stories start to diverge quite a bit.

In the book, Carter instantly realizes he’s landed on Mars; in the movie, he has some trouble figuring it out. I’m glad the filmmakers chose to include Carter’s gravity lessons—they’re hilarious to watch.

There are several ways the movie departs from the book. In the movie, the Red Men of Mars don’t look all that red, the ships don’t look like flying boats and the warrior Martian Tars Tarkas knows all about his daughter Sola from the beginning.  Do all those changes make John Carter a bad movie?  Not necessarily.  I thought the movie was a lot of fun, especially seeing it in an IMAX theater. But it probably won’t win an Oscar.

Some of the film’s changes don’t make sense. In the novels—there are 11 books Burroughs’ Barsoom series—Carter doesn’t meet the Therns until the second book. Introducing the Therns in the film seemed to needlessly complicate the story. Also, since when is Zodonga a giant mechanized city roaming the wastes like an enormous robot scorpion?

I would’ve liked to see the movie stay truer to its roots.  The book is a real piece of history, something we sci-fi nerds hold sacred. Did you know that one of the things that inspired Carl Sagan to get into the field of science was reading Edgar Rice Burroughs’s work?  Sagan had a map of Barsoom hanging outside his office for two decades.  Burroughs also inspired legendary science fiction authors Ray Bradbury, Robert A. Heinlein and Arthur C. Clarke. Finished in 1912, A Princess of Mars helped give birth to modern science fiction.

Every serious sci-fi fan should read the entire Barsoom series.  The books are worth reading for the historical value alone. It’s fascinating to see where the genre started compared to where we are today.  Jules Verne opened the doors, and Edgar Rice Burroughs (or ERB, as he is more affectionately known) reached the masses.  It’s no wonder scientists named a crater on Mars after him.

Quinton Lawman is a technical writer at OverDrive.