Erriapus

Erriapus is a small, irregular retrograde satellite of the planet Saturn. It is also known as Saturn XXVIII.

Discovery and Naming: Erriapus was discovered on September 23, 2000, by Brett J. Gladman, John J. Kavelaars, Jean-Marc Petit, Hans Scholl, Matthew J. Holman, Brian G. Marsden, Phillip D. Nicholson, and Joseph A. Burns using telescopes at the Mauna Kea Observatories in Hawaii. It was initially designated as S/2000 S8.

The name Erriapus was officially assigned in August 2003. It is named after Erriapus, a giant in Gallic mythology. The retrograde irregular satellites of Saturn are generally named after giants from Gallic, Norse, or Inuit mythology.

Orbital Characteristics: Erriapus orbits Saturn at an average distance of approximately 17.3 million kilometers. Its orbit is highly inclined (around 34 degrees) and eccentric (with an eccentricity of approximately 0.47). It takes roughly 871 Earth days to complete one orbit around Saturn. Due to its irregular orbit and retrograde motion (orbiting in the opposite direction of Saturn's rotation), Erriapus is classified as a member of the Gallic group of irregular satellites.

Physical Characteristics: Erriapus is a small satellite, with an estimated diameter of about 10 kilometers. Its surface is believed to be dark, reflecting only a small percentage of sunlight. Its composition is largely unknown, but it is likely to be primarily composed of ice and rock, similar to other irregular satellites in the outer Solar System.

Classification: Erriapus belongs to the Gallic group of irregular satellites orbiting Saturn. These satellites share similar orbital characteristics and may have originated from the breakup of a larger parent body.