Home > Tethys (moon)
Tethys
|
|
| Discovery
|
| Discovered by
| Giovanni Cassini
|
| Discovered in
| 1684
|
| Orbital characteristics
|
| Semimajor axis
| 294,660 km
|
| Eccentricity
| 0.000
|
| Orbital period
| 45h 18m 26s
|
| Inclination
| 1.09°
|
| Is a satellite of
| Saturn
|
| Physical characteristics
|
| Mean diameter
| 1059.8 km
|
| Mass
| 6.176×1020 kg
|
| Mean density
| 0.99 g/cm3
|
| Surface gravity
| 0.16 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).
| 45h 18m 26s
( synchronousIn astronomy, synchronous rotation is a planetological term describing a body orbiting another, where the orbiting body takes as long to rotate on its axis as it does to make one orbit; and therefore always keeps the same hemisphere pointed at the body it)
|
| 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
| 0.034°
|
| 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
| 0.8
|
| Surface temp.Temperature is the physical property of a system which underlies the common notions of "hot" and "cold"; the material with the higher temperature is said to be hotter. General description The formal properties of temperature are studied in thermodynamics.
|
| min | mean | max
|
| ? K | 86 KThe kelvin (symbol: K is the SI unit of temperature, and is one of the seven SI base units. It is defined by two facts: zero kelvin is absolute zero (when molecular motion stops), and one kelvin is the fraction 1/273. 16 of the thermodynamic temperature o | ? K
|
|
| Atmosphere
| none
|
Tethys ("TETH iss" or "TEE thiss") is a moon of Saturn that was discovered by Giovanni Domenico Cassini in 1684.
1 Name
Tethys is named after the titan Tethys of Greek mythology. It is also designated Saturn III. It should not be confused with the asteroid 17 Thetis.
Cassini named the four moons he discovered (Tethys, Dione, Rhea and Iapetus) Lodicea Sidera ("the stars of Louis") to honour king Louis XIV. Astronomers fell into the habit of referring to them and Titan as Saturn 1 through Saturn 5. Once Mimas and Enceladus were discovered, in 1789, the numbering scheme was extended to Saturn 7.
The names of all seven satellites of Saturn then known come from John Herschel (son of William Herschel, discoverer of Mimas and Enceladus) in his 1847 publication Results of Astronomical Observations made at the Cape of Good Hope[1], wherein he suggested the names of the Titans, sisters and brothers of Cronos (the Greek Saturn), be used.
