| • Science | • People | • Locations | • Timeline |
| Discovery | |
|---|---|
| Discovered by | Bond, Bond & Lassell |
| Discovered on | 1848 September 16 |
| Orbital characteristics | |
| Semimajor axis | 1,464,100 km |
| Eccentricity | 0.0175 |
| Orbital period | 21.280 d |
| Inclination | 0.568° |
| Is a satellite of | Saturn |
| Physical characteristics | |
| Mean diameter | 266 km |
| Mass | 1.08×1019 kgThe kilogram (symbol: kg is the SI base unit of mass. A gram is defined as one thousandth of a kilogram. Conversion of units describes equivalent units of mass in other systems. Multiples SI prefixes are used to name multiples and subdivisions of the kilo |
| Mean densityFor other meanings of density, see density (disambiguation Density (symbol: rho Greek: rho) is a measure of mass per unit of volume. The higher an object's density, the higher its mass per volume. The average density of an object equals its total mass div | 1.1 g/cm3 |
| Surface gravityThis article covers the physics of gravitation. See also gravity (disambiguation). Gravitation is the tendency of masses to move toward each other. The first mathematical formulation of the theory of gravitation was made by Sir Isaac Newton and proved ast | 0.041 m/s2In physics, acceleration (symbol: a is defined as the rate of change (or time derivative) of velocity. It is thus a vector quantity with dimension length/ time˛. In SI units, this is metre/second˛. To accelerate an object is to change its velocity over a |
| Rotation periodprograde planet like the Earth, the sidereal day is shorter than the solar day. At time 1, the sun and a certain distant star are both overhead. At time 2, the planet has rotated 360° and the distant star is overhead again (1→2 one sidereal day). | chaoticChaos theory in mathematics and physics, deals with the behaviour of certain nonlinear dynamical systems that (under certain conditions) exhibit the phenomenon known as chaos most famously characterised by sensitivity to initial conditions (see butterfly |
| Axial tiltAxial tilt is an astronomical term regarding the inclination angle of a planet's rotation axis in relation to its orbital plane. It is also called obliquity . A planet whose rotation axis were perpendicular to the orbital plane would have an axial tilt of | variable |
| AlbedoNote: This article discusses the physical or planetological property of albedo. For other usage, see Albedo (disambiguation). The albedo is a measure of reflectivity of a surface or body. It is the ratio of electromagnetic radiation reflected to the amoun | 0.25 |
| Atmosphere | no atmosphere |
Hyperion ("hy PEER ee un") is a moon of Saturn discovered by William Cranch Bond, George Phillips Bond and William Lassell in 1848. It is named after Hyperion, a Titan in Greek mythology. It is also designated Saturn VII.
Hyperion's discovery came not too long after John Herschel had suggested names for all seven previously-known satellites of Saturn in his 1847 publication Results of Astronomical Observations made at the Cape of Good Hope. [1] Lassell, who saw Hyperion two days after the Bonds, had already endorsed Herschel's naming scheme and suggested the name Hyperion in accordance with it. He also beat the Bonds to publication.
The Cassini orbiter is due to perform a flyby of Hyperion on September 25, 2005.