PASADENA, Calif., May 11 (UPI) -- NASA says it appears flash flooding has paved streambeds in the Xanadu region of Saturn's moon Titan, producing thousands of sparkling crystal balls of ice.
The space agency said its Cassini spacecraft obtained the images and scientists, analyzing the way the terrain has scattered radar beams, deduced the spheres likely originated as part of water-ice bedrock in higher terrain in Xanadu, they said.
"What we believe happened in this area is a lot like what creates polished river rocks on Earth," said Alice Le Gall of NASA's Jet Propulsion Laboratory, the study's lead author. "Bouncing downstream smooths out the edges of rocks."
Le Gall and colleagues conclude the most plausible explanation for the extreme brightness of the Xanadu channels is a collection of transparent spherical sediments, packed more tightly together.
The researchers said the spheres appear to be made of water ice frozen at about minus 290 degrees Fahrenheit, rather than from mineral rocks such as on Earth. And they might be doped with ammonia that would look bright to Cassini's radar.
"It's been really hard for a long time for people to understand why Xanadu is so bright," said Steve Wall, a radar team member at JPL. "You might not expect these kinds of geometries in a natural setting, but we believe this can explain the enigma."
The study appears in the early online edition of the journal Icarus.
