Tethys (moon) - Discovery and Naming

Discovery and Naming

Tethys was discovered by Giovanni Domenico Cassini in 1684 together with Dione, another moon of Saturn. He had also discovered two moons, Rhea and Iapetus earlier, in 1671–72. Cassini observed all these moons using a large aerial telescope he set up on the grounds of the Paris Observatory.

Cassini named the four new moons as Sidera Lodoicea ("the stars of Louis") to honour king Louis XIV of France. By the end of the seventeenth century, astronomers fell into the habit of referring to them and Titan as Saturn I through Saturn V (Tethys, Dione, Rhea, Titan, Iapetus). Once Mimas and Enceladus were discovered in 1789, the numbering scheme was extended to Saturn VII by bumping the older five moons up two slots. The discovery of Hyperion in 1848 changed the numbers one last time, bumping Iapetus up to Saturn VIII. Henceforth, the numbering scheme would remain fixed.

The modern names of all seven satellites of Saturn 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, he suggested the names of the Titans, sisters and brothers of Kronos (the Greek analogue of Saturn), be used.

Tethys is named after the titan Tethys of Greek mythology. It is also designated Saturn III or S III Tethys. The correct adjectival form of the moon's name is Tethyan, although other forms are also used.

Read more about this topic:  Tethys (moon)

Famous quotes containing the words discovery and/or naming:

    The gain is not the having of children; it is the discovery of love and how to be loving.
    Polly Berrien Berends (20th century)

    See, see where Christ’s blood streams in the firmament!
    One drop would save my soul—half a drop! ah, my Christ!—
    Ah, rend not my heart for naming of my Christ!—
    Yet will I call on him!—O, spare me, Lucifer!—
    Where is it now? ‘T is gone; and see where God
    Stretcheth out his arm, and bends his ireful brows!—
    Mountains and hills, come, come and fall on me,
    And hide me from the heavy wrath of God!
    Christopher Marlowe (1564–1593)