On October 30th my second favorite space-western, the Mandalorian, started its second season with a bang. While watching the main character, Mando, fly around the sands of Tatooine with his pint-sized Yoda sidekick I thought it would be fun to write about the science side of the galaxy far far away. The first episode of the season featured a few things that are scientifically questionable, but for now I am just going to talk about one of them. The Greater Krayt Dragon looks amazing, but I can’t help but wonder if something that large would be able to swim through sand. Let’s look at the science involved.
For the record, I love this show and I don’t think there is anything wrong with being critical of shows or movies as long as our arguments are well-founded. Caution Spoilers Ahead!
In episode one of season two, we see our heroes face off against a Greater Krayt Dragon on the desert planet of Tatooine. The giant creature is terrorizing a local mining town and will eventually, because of its size and appetite, destroy and kill everyone in the area. Our hero agrees to help kill the beast and save the town in exchange for some old rusty armor that looks like it crawled out of a Sarlacc pit. Unfortunately, killing this monster is a difficult task because it swims beneath the surface of the sand and seems to only pop up to eat the occasional Bantha.
But can a giant monster really swim in desert sands? Is this even slightly scientifically plausible or is this all for the sake of looking cool? To answer these questions, I enlisted the help of Josh Mead, a Ph.D. student in ecology and evolutionary biology at the University of Texas at El Paso. John knows a thing or two about similar creatures and after a short chat, he gave me some really helpful information.
The science behind swimming through sand
According to Josh, several creatures on Earth have the ability to swim through sand. They are often small creatures whose bodies have unique characteristics that help them accomplish this feat. To help explain how these creatures work Josh chose the example of Scincus Scincus or sandfish. These tiny lizards live in the desert sands of Northern Africa and the Middle East where they spend most of their time under the surface. They are able to move through the sand easily because of smooth friction-reducing scales and fish like wiggling. The scales reduce the amount of friction and the wiggling pushes the sand out of the way and moves the lizard forward at great speed. Both of these features are essential for being able to dive quickly into the sand and although sandfish have legs, they do very little to help with swimming. They also have a wedge-shaped head and recessed jaw help that helps them swim at a speed of 2 body lengths a second without getting a mouth full of sand.
In addition to those features, the way sandfish breathe has been adapted to life below the surface. As Josh explains “When one of these species breathes, its method of ventilation is not simply expansion and contraction of the ribs as seen in most reptiles, as this would immediately fill their lungs with sand in this environment. Instead, their ventilation moves the underside of the animal to prevent the collapse of sand when breathing.”
It would seem that swimming through sand is in fact, scientifically possible as long as the animal in question has a body that is designed to handle the environment.
What about the Greater Krayt Dragon?
The greater Krayt Dragons of Tatooine are slightly different than the sand swimming animals on Earth. The first thing I noticed is that the skin of the dragon seems to be covered in rough scales, large horns, and the teeth seem to stick out a great deal. These features would only serve to slow the creature down as it swims in the sand. The head does have a wedge-like shape, but the mouth seems to stick out below the snout which would result in a mouth full of sand as it moves forward. Also, judging by the fact that our heroes can hear the creature breathing at a great distance means that the dragon’s breathing does not work like the sandfish and would most likely scare off potential prey. Furthermore, in this episode, we see the dragon tunnel through the side of a rock formation in mere seconds. This goes against everything we know about sand swimmers who prefer to live in finer sands.
In the end, there is just no way that the Krayt Dragon would be able to swim through the sand at a decent speed and because of that, I have to give it a grade of D+ for poor scientific plausibility. Whereas we know that the concept of creatures swimming through sand is scientifically sound, it seems that this creature was designed to make it as hard as possible. It would need a smoother body, a reshaping of its mouth, and a completely different respiratory system.
All things considered, I would have given it a lower grade but since it is possible for something like this to exist (minus the rock tunneling) and the movement and behavior of the creature felt real in the context of the story I think we can cut it some slack.