Terrain on a planetary surface that consists of belts of near-parallel grooves. The term was first used to describe the grooves on Phobos. Since then it has been applied to grooved areas on Ganymede and on other satellites and asteroids. These terrains have different characteristics and origins, even on the same body. Some appear to be parallel lines of secondary impact craters, while others are tectonic features.
Subjects: Astronomy and Astrophysics.