Ọ bụ ọnwa nke abụọ kachasị ukwuu na Solar System mgbe ọnwa Jupiter bụ Ganymede, ma buru ibu karịa mbara ala Mercury, mana ọ bụ naanị 40% dị ka oke. Achọpụtara na 1655 site n'aka onye na-enyocha mbara igwe Dutch bụ Christiaan Huygens, Titan bụ ọnwa mbụ a maara nke Saturn, na nke isii a maara nke mbara ala (mgbe ọnwa nke ụwa na ọnwa anọ nke Jupiter). Titan na-agbagharị Saturn na 20 radii. Site n'elu Titan, Saturn na-eme ka ọ bụrụ 5.09 degrees ma ga-apụta na mbara igwe karịa 11.4 ugboro karịa ụwa site na ọnwa.
Titan