Themisto

Themisto, a diminutive irregular moon of Jupiter, was discovered in 1975 by American astronomers Charles T. Kowal and Elizabeth Roemer. With an estimated diameter of about 8 kilometers (5 miles), Themisto boasts an irregular shape and a distinctively small size compared to its larger Jovian counterparts. Its orbital behavior sets it apart, following a distant and eccentric orbit around Jupiter. This orbit aligns Themisto with the characteristics of the Themisto Group, a collection of irregular moons with similar orbital traits. Despite its historical significance, limited information is available about Themisto's surface characteristics and composition due to its size and distance from Earth. The moon's origin is tied to theories of tidal forces from Jupiter or collisions with other objects, which may have shattered a larger moon into the irregular fragments seen today.