S/2007 S2 is a member of the Norse group of moons, which orbit Saturn at mean distances ranging from 12 to 24 million km, at inclinations between 136 and 176 degrees from the plane of Saturn's equator, and with eccentricities between 0.12 and 0.77. (A satellite's eccentricity is a number between 0 and 1 which describes the shape of the orbit. The closer to 0, the more circular it is; the closer to 1, the more elongated.)
The Norse moons all have retrograde orbits (they travel around Saturn in the opposite direction from the planet's rotation). That and their deviations from circular orbits and from the plane of Saturn's equator classify them as "irregular" satellites. Like Saturn's other irregular moons, they are thought to be objects that were 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.
Unlike the Gallic and Inuit groups of Saturn's moons, the wide range of distances, inclinations and eccentricities among moons in the Norse group suggest that they are not the pieces of a single original object that shattered in a collision, but they may be the pieces of several such "original" objects.
S/2007 S2 is thought to have a mean radius of about 3 km, assuming an albedo 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 16.7 million km from Saturn, the satellite takes about 808 Earth days to complete one orbit.
Discovery:
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.
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.
