Hyperion with image processing to bring out details. Taken by the Cassini space probe. Image source: [1]
Discovered in 2005, Hyperion is shaped like a potato and, with dimensions of 410 x 260 x 220 km, is one of the largest irregular bodies of the Solar System. It is the fragment of a much larger satellite, which must have had a great impact in the past to break into a thousand pieces.
Its main feature is a large crater, more than 120 km in diameter and almost 10 km deep, which stands out on its surface. As if it were a gigantic gruyere cheese, Hyperion has a porous texture, with holes and hollows of all sizes, even below the surface. This gives it the extraordinary characteristic that, despite being a solid object, a mixture of ice and rock, it only has half the density of the water.
Hyperion revolves around Saturn at an average distance of a million and a half km. And it takes slightly more than 21 days to perform a complete orbit. It is the next 'classic' moon of Saturn after Titan. One of the most peculiar features of Hyperion's orbit is that it is in a 4:3 orbital resonance with respect to Titan, which means that the latter orbits exactly four times around Saturn for every 3 turns of Hyperion
More details here: Hyperion
Hyperion with image processing to bring out details. Taken by the Cassini space probe. Image source: [2]
Hyperion - close-up view From 38,000 km (24,000 mi) (31 May 2015). Image source: [3]