PLANETS & MOONS A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site Helene Helene imaged from a distance of 340,000 km by Voyager 2 A small moon of Saturn. It was discovered on March 1, 1980, from ground-based observations at Pic du Midi Observatory and is also known as Saturn XII. It is said to be a Dione trojan because it shares the same orbit as its larger companion, preceding it by 60°. Large portions of Helene appear to have been blasted away by impacts. Discovery 1980, by P. Laques and J. Lecacheux Semimajor axis 377,396 km (234,553 miles) Diameter 36 × 32 × 30 km (22 × 20 × 19 miles) Orbital period 2.737 days (2 days 17 hr 41 min.) Orbital eccentricity 0.002 Orbital inclination 0.2° Related entry    • Saturn, moons Related category    • PLANETS AND MOONS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP