Built in the sands of the windy Tunisian desert, Mos Espa is a fictional city used in filming "Star Wars Episode 1: The Phantom Menace." But the remote Mos Espa isn't long for this world. It's about to be buried by an enormous crescent-shaped sand dune called a barchan.
This has proved a boon for a team of geomorphologists, who recently used the 1999 movie's Mos Espa set as a key part of their study on barchan migration. Barchans, like other sand dunes, move via wind. Their migration across deserts can often make them seem alive.
But measuring the progress of migrating sand dunes presents difficulties. "Dunes often appear in vast sand seas where not only can it be difficult to tell one dune from another, but there may be no fixed reference point against which to measure the dune’s position." Ralph Lorenz, one of the study's authors, wrote in a blog post for the Planetary Society.
The solution? Measure the sand dunes near Mos Espa, which lies between the arms of a large barchan dune and near two other dunes. The famous set provides a fixed reference point, visible on Google Earth satellite images as well as on abundant tourist photos.
Lorenz, of Johns Hopkins University’s Applied Physics Laboratory, and his fellow geomorphologists found that the dunes around Mos Espa move approximately 50 feet per year. Currently, the closest dune is only 33 feet from Mos Espa.
In their paper, the scientists raise the question of whether Mos Espa can be saved. The answer: probably not. "Even if the threatening barchan fizzles out as it meets the set," Lorenz writes, "a larger, slower-moving barchan is lumbering behind it."