Hyperion's unusual craters (1) - HR

Original caption:"This HR Cassini mosaic shows that Hyperion truly has a surface different from any other in the Saturn System. The mosaic is composed of 5 clear filter images taken during Cassini's close flyby of Hyperion on Sept. 26, 2005. The spacecraft passed approximately 500 Km(310 miles) above the moon's surface. Hyperion is 266 Km (about 165 miles) in diameter.
Scientists are extremely curious to learn what the dark material is that fills many craters on this oddball moon. Features within the dark terrain, including a 200-meter-wide impact crater surrounded by rays to the right of center (Sezione 3 del frame) and numerous bright-rimmed craters, indicate that the dark material may be only tens of meters (hundreds of feet) thick with brighter material beneath".