S/2007 S2 was discovered in 2007 by Scott S. Sheppard, David L. Jewitt and Jan T. Kleyna using the Subaru 8.2-meter reflector at the Mauna Kea Observatory on the island of Hawaii.
Not yet officially named, S/2007 S2 is thought to have a mean radius of 1.9 miles (3 kilometers), assuming an albedo (a measure of how reflective the surface is) of 0.04. It orbits Saturn at an inclination of about 176 degrees and an eccentricity of about 0.2. At a mean distance of 10.4 million miles (16.7 million kilometers) from Saturn, the satellite takes about 808 Earth days to complete one orbit.
S/2007 S2 is a member of the Norse group of moons. These irregular satellites have retrograde orbits around Saturn -- traveling around in the opposite direction from the planet's rotation. S/2007 S2 and the other Norse moons also have eccentric orbits, meaning they are more elongated than circular.
Like Saturn's other irregular moons, S/2007 S2 is thought to be an object that was captured by Saturn's gravity, rather than having accreted from the dusty disk that surrounded the newly formed planet as the regular satellites are thought to have done.
How S/2007 S2 Got its Name
S/2007 S2 was so designated because it is a satellite (S) that was discovered in 2007, and was the 2nd satellite of Saturn (S) to be found that year.