Prometheus (moon) explained

Prometheus
Pronounced:	^[1]
Adjective:	Promethean, -ian ^[2]
Named After:	Προμηθεύς Promētheys
Mpc Name:	Saturn XVI
Discoverer:	Stewart A. Collins D. Carlson Voyager 1
Discovered:	24 October 1980
Satellite Of:	Saturn
Dimensions:	km (± km)
Escape Velocity:	km/s at longest axis to km/s at poles
Rotation:	synchronous
Axial Tilt:	assumed zero
Single Temperature:	≈ 74 K

Prometheus is an inner satellite of Saturn. It was discovered on 24 October 1980 from images taken by the Voyager 1 probe, and was provisionally designated . In late 1985 it was officially named after Prometheus, a Titan in Greek mythology. It is also designated .

Prometheus is extremely elongated, measuring approximately NaNkm (-2,147,483,648miles). The surface is heavily cratered, giving it a similar appearance to nearby Epimetheus and Janus. It has several ridges and valleys and a number of impact craters of about 20km (10miles) diameter are visible. From its very low density and relatively high albedo, it is likely that Prometheus is a very porous icy body.

Interactions with F Ring and other moons

Prometheus is a shepherd satellite for the inner edge of Saturn's narrow F Ring. Pandora orbits just outside the F Ring, and has traditionally been viewed as an outer shepherd of the ring; however, recent studies indicate that only Prometheus contributes to the confinement of the ring.^[3] ^[4]

Images from the Cassini probe show that Prometheus's gravitational influence creates kinks and knots in the F Ring as it shepherds material from it. The orbit of Prometheus appears to be chaotic, due to a series of four 121:118 mean-motion resonances with Pandora. The most appreciable changes in their orbits occur approximately every 6.2 years, when the periapsis of Pandora lines up with the apoapsis of Prometheus, as they approach to within approximately 1400 km. Prometheus is itself a significant perturber of Atlas, with which it is in a 53:54 mean-longitude resonance.

Prometheus also participates in a 17:15 mean-motion resonance with Epimetheus, but only while it is on the outer orbit relative to Janus. No such configuration with Janus exists.^[5]

Physical characteristics

The surface of Prometheus can be distinguished into two types of terrain, both equally cratered and separated from each other by long scarps, one of which could be indicative of an exposed core section. This core section would make up roughly two-thirds of the total volume of Prometheus.

Prometheus' elongated shape could be a result of the low-speed merging of several similar-sized bodies.

Gallery

Animations

References

Sources

Marsden . Brian G. . Satellites of Saturn . October 31, 1980 . discovery . IAU Circular . 3532 . 2011-12-29 . .
Marsden . Brian G. . Satellites of Saturn and Pluto . January 3, 1986 . naming the moon . IAU Circular . 4157 . 2011-12-29 . .
10.1016/j.icarus.2004.09.005. Renner. Stéfan F.. Sicardy. Bruno. French. Richard G.. March 2005. Prometheus and Pandora: Masses and orbital positions during the Cassini tour. Icarus. 174. 1. 230–240. 2005Icar..174..230R. .
10.1086/505206. Spitale. J. N.. Jacobson. R. A.. Porco. C. C.. Owen. W. M. Jr. . 2006. The orbits of Saturn's small satellites derived from combined historic and Cassini imaging observations. The Astronomical Journal. 132. 2. 692–710. 2006AJ....132..692S. . free.
10.1016/j.icarus.2010.01.025. Thomas. P. C.. July 2010. Sizes, shapes, and derived properties of the saturnian satellites after the Cassini nominal mission. Icarus. 208. 1. 395–401. 2010Icar..208..395T. 2015-09-04. 2018-12-23. https://web.archive.org/web/20181223003125/http://www.ciclops.org/media/sp/2011/6794_16344_0.pdf. dead.
Web site: . Planet and Satellite Names and Discoverers . July 21, 2006 . USGS Astrogeology . Gazetteer of Planetary Nomenclature . 2011-12-29 . .
. P. C. . Thomas . P. . Helfenstein . The small inner satellites of Saturn: Shapes, structures and some implications . Icarus . July 2020 . 344 . 113355 . 20 . 10.1016/j.icarus.2019.06.016 . 2020Icar..34413355T. 197474587 .
. V. . Lainey . N. . Rambaux . N. . Cooper . R. . Dahoumane . Q. . Zhang . Characterising the interior of five inner Saturnian moons using Cassini ISS data . Astronomy & Astrophysics . February 2023 . 670 . L25 . 6 . free . 10.1051/0004-6361/202244757 . 2023A&A...670L..25L.
. Thomas . P. C. . Burns . J. A. . Hedman . M. . Helfenstein . P. . Morrison . S. . Tiscareno . M. S. . Veverka . J. . 2013-09-01 . The inner small satellites of Saturn: A variety of worlds . Icarus . 226 . 1 . 999–1019 . 10.1016/j.icarus.2013.07.022 . 0019-1035. subscription .
. The Origin and Composition of Saturn’s Ring Moons. Space Science Reviews. 2024-09-17. 1572-9672. 72. 220. 7. 10.1007/s11214-024-01103-z. en. Mauro. Ciarniello. Gianrico. Filacchione. Philip D.. Nicholson. Matthew M.. Hedman. Sebastien. Charnoz. Jeffrey N.. Cuzzi. Maryame. El Moutamid. Amanda R.. Hendrix. Nicolas. Rambaux. Kelly E.. Miller. Olivier. Mousis. Kevin. Baillié. Paul R.. Estrada. J. Hunter. Waite. free.

External links

Web site: Cassini–Huygens: Multimedia-Videos / Soft Collision . . https://web.archive.org/web/20071029205038/http://saturn.jpl.nasa.gov/multimedia/videos/video-details.cfm?videoID=163 . 29 October 2007 . Prometheus slowly collides with the diffuse inner edge of Saturn's F ring ... pulls a streamer of material from the ring and leaves behind a dark channel..
Prometheus Profile at NASA's Solar System Exploration site
The Planetary Society: Prometheus
3-D anaglyph view of Prometheus

Notes and References

Encyclopedia: Prometheus . https://web.archive.org/web/20200320063552/https://www.lexico.com/definition/prometheus . dead . March 20, 2020 . Lexico UK English Dictionary . Oxford University Press.
Encyclopedia: Promethean . https://web.archive.org/web/20200320063559/https://www.lexico.com/definition/promethean . dead . March 20, 2020 . Lexico UK English Dictionary UK English Dictionary . Oxford University Press.
Web site: Lakdawalla . E. . Emily Lakdawalla . On the masses and motions of mini-moons: Pandora's not a "shepherd", but Prometheus still is . . 2014-07-05 . 2015-04-17 .
Cuzzi. J. N.. Whizin. A. D.. Hogan. R. C.. Dobrovolskis. A. R.. Dones. L. . Showalter. M. R.. Colwell. J. E.. Scargle. J. D.. Saturn's F Ring core: Calm in the midst of chaos. Icarus. 232. April 2014. 157–175. 0019-1035. 10.1016/j.icarus.2013.12.027. 2014Icar..232..157C .
Cooper . N. J. . Renner . S. . Murray . C. D. . Evans . M. W. . 2014-12-24 . SATURNʼS INNER SATELLITES: ORBITS, MASSES, AND THE CHAOTIC MOTION OF ATLAS FROM NEW CASSINI IMAGING OBSERVATIONS . The Astronomical Journal . 149 . 1 . 27 . 1406.6492 . 10.1088/0004-6256/149/1/27 . 1538-3881 . free.