Scientists had previously favored the idea that a natural force recently carved both the canyon and pinwheel pattern into older geological deposits. But they could not test their theories beyond what they could see on the Martian surface, as if trying to judge a book by its cover.
"Radar is like opening the book; we can read each page now," said Isaac Smith, a planetary scientist at the University of Texas Austin. "People were looking at the outside and thinking they knew what the book was about, but they didn't."
Such technology allowed scientists to take 2-D cross-section images of the troughs and reveal the layers within the walls, like snapshots in time going back through the red planet's history. Radar also helped trace reflective markers that followed the geometry of underground structures to build up a 3-D sense of the layers.
The radar studies do not answer the riddle of what changes in the Martian atmosphere spurred the formation of both the canyon and the younger spiraling troughs. But they do give scientists a new understanding of the timing of the processes that allow the wind and sun to shape the Martian surface over a certain period, and that may lead to more evidence-based climate models for the red planet.
