Rings of Saturn

Saturn has the most extensive and complex ring system of any planet in the Solar System. The rings consist of particles in orbit around the planet and are made almost entirely of water ice, with a trace component of rocky material. Particles range from micrometers to meters in size.[1] There is no consensus as to what mechanism facilitated their formation: while investigations using theoretical models suggested they formed early in the Solar System's existence,[2] newer data from Cassini suggests a more recent date of formation.[3] In September 2023, astronomers reported studies suggesting that the rings of Saturn may have resulted from the collision of two moons "a few hundred million years ago,".[4][5]

Though light reflected from the rings increases Saturn's apparent brightness, they are not themselves visible from Earth with the naked eye. In 1610, the year after his first observations with a telescope, Galileo Galilei became the first person to observe Saturn's rings, though he could not see them well enough to discern their true nature. In 1655, Christiaan Huygens was the first person to describe them as a disk surrounding Saturn.[6] The concept that Saturn's rings are made up of a series of tiny ringlets can be traced to Pierre-Simon Laplace,[6] although true gaps are few – it is more correct to think of the rings as an annular disk with concentric local maxima and minima in density and brightness.[2]

The rings have numerous gaps where particle density drops sharply: two opened by known moons embedded within them, and many others at locations of known destabilizing orbital resonances with the moons of Saturn. Other gaps remain unexplained. Stabilizing resonances, on the other hand, are responsible for the longevity of several rings, such as the Titan Ringlet and the G Ring. Well beyond the main rings is the Phoebe ring, which is presumed to originate from Phoebe and thus share its retrograde orbital motion. It is aligned with the plane of Saturn's orbit. Saturn has an axial tilt of 27 degrees, so this ring is tilted at an angle of 27 degrees to the more visible rings orbiting above Saturn's equator.

  1. ^ Porco, Carolyn (2022-07-05). "Common Questions". CICLOPS Cassini Imaging Central Laboratory for Operations. Archived from the original on 2023-08-01. Retrieved 2022-09-22.
  2. ^ a b Tiscareno, M. S. (2012). "Planetary Rings". In Kalas, P.; French, L. (eds.). Planets, Stars and Stellar Systems. Springer. pp. 61–63. arXiv:1112.3305v2. doi:10.1007/978-94-007-5606-9_7. ISBN 978-94-007-5605-2. S2CID 118494597.
  3. ^ Iess, L.; Militzer, B.; Kaspi, Y.; Nicholson, P.; Durante, D.; Racioppa, P.; Anabtawi, A.; Galanti, E.; Hubbard, W.; Mariani, M. J.; Tortora, P.; Wahl, S.; Zannoni, M. (2019). "Measurement and implications of Saturn's gravity field and ring mass". Science. 364 (6445): eaat2965. Bibcode:2019Sci...364.2965I. doi:10.1126/science.aat2965. hdl:10150/633328. PMID 30655447. S2CID 58631177.{{cite journal}}: CS1 maint: article number as page number (link)
  4. ^ Cite error: The named reference TAJ-20230927 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference NYT-210230928 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference history_of_the_rings was invoked but never defined (see the help page).
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