The dune was measured at 20 feet tall and 300 feet wide in 2009, and it's been moving toward the set about 50 feet per year since 2002, she said. Research by her and two colleagues was recently published in the journal Geomorphology.
"In terms of geologic time scales, it's one of the fastest things we see happen, aside from lava flows and landslides," Radebaugh said. "You can compare it to some glaciers, but even most glaciers tend to move slower."
The set began attracting tourists in 1999 following release of "Episode 1: The Phantom Menace." Before that, fans had visited some of the 1970s-era sets of later episodes, which have since been overrun by dunes.
The set, a fictional spaceport left behind after filming at the request of Tunisian tourist officials, draws about 100,000 visitors annually.
Radebaugh said bulldozing the dune to save the set isn't an option because a larger dune follows behind. The most feasible plan to save the site would require moving everything 650 feet to the south, she added.
But it may be too late for a rescue because one dwelling and a pair of other structures already are partially buried.
"Sometimes we just have to move out of the way," Radebaugh said. "The sand people in Star Wars are nomads, right? Maybe they are nomads because the sand moves."
Ironically, she credits the Star Wars films for sparking her interest in planetary science. Radebaugh, an associate professor of geological sciences, usually teams up with NASA to study moons of Saturn and Jupiter. But a visit to Tunisia with other planetary scientists prompted the dune research.
"It's so fun to see geology in action," she said. "We live on a dynamic planet."