Fainter planetary rings can form as a result of meteoroid impacts with moons orbiting around the planet or, in case of Saturn's E-ring, the ejecta of cryovolcanic material. [5] [6] It can be used as a sun dial to tell time, if the approximate latitude and season is known, or to tell latitude, if the time is known or observed (at solar noon). It may be considered to be a simplified, portable armillary sphere, or a more complex form of astrolabe. A ring system is a disc or ring, orbiting an astronomical object, that is composed of solid material such as dust and moonlets, and is a common component of satellite systems around giant planets like Saturn. A ring system around a planet is also known as a planetary ring system. [1] The altitude of the sun does not change much in a single day at the poles (where the sun rises and sets once a year), so rough measurements of solar altitude don't vary with time of day at high latitudes.

Morgado, B. E.; etal. (2023). "A dense ring of the trans-Neptunian object Quaoar outside its Roche limit". Nature. 614 (7947): 239–243. Bibcode: 2023Natur.614..239M. doi: 10.1038/s41586-022-05629-6. hdl: 10023/27188. PMID 36755175. S2CID 256667345. Others have been found to be engraved with two twelve-hour time scales. Each twelve-hour scale is stretched over 180 degrees and numbered by hour with hashes every 20 minutes and smaller hashes every four minutes. The inside displays a calendrical scale with the names of the months indicated by their first letters, with a mark to show every 5 days and other marks to represent single days. On these, the outside of the ring is engraved with the corresponding symbols of the zodiac signs. The position of the symbol indicates the date of the entry of the sun into this particular sign. The vernal equinox is marked at March 15 and the autumnal equinox is marked at September 10. [7] Declination ring [ edit ] Astronomical ring with an alidade on the declination ring (folded closed). A ring is a collection of vast numbers of particles, each like a tiny moon obeying Kepler’s laws as it follows its own orbit around the planet. Thus, the inner particles revolve faster than those farther out, and the ring as a whole does not rotate as a solid body. In fact, it is better not to think of a ring rotating at all, but rather to consider the revolution (or motion in orbit) of its individual moonlets.It had been theorized by some astronomers that Pluto might have a ring system. [24] However, this possibility has been ruled out by New Horizons, which would have detected any such ring system. The smaller circle within the larger one is the zodiacal ring, and is surrounded by the twelve signs of the zodiac. a b Devlin, Hannah (8 February 2023). "Ring discovered around dwarf planet Quaoar confounds theories". The Guardian. Archived from the original on 8 February 2023 . Retrieved 8 February 2023. The fine Art Nouveau statue of him and his followers by Ladislav Šaloun dominates the north side of the square. A classic sunrise on Charles Bridge A classic Charles Bridge sunset from the Old Town Bridge Tower There are two basic ideas of how such rings come to be. First is the breakup hypothesis, which suggests that the rings are the remains of a shattered moon. A passing comet or asteroid might have collided with the moon, breaking it into pieces. Tidal forces then pulled the fragments apart, and they dispersed into a disk. The second hypothesis, which takes the reverse perspective, suggests that the rings are made of particles that were unable to come together to form a moon in the first place.

NASA - Saturn's Moon Rhea Also May Have Rings". Archived from the original on 2012-10-22 . Retrieved 2010-09-16. NASA– Saturn's Moon Rhea Also May Have Rings Leah Crane (Feb 18, 2023). "Weird dust ring orbits the sun alongside Mercury and we don't know why". New Scientist. Ring systems of planets [ edit ] The ring orbiting Saturn consists mostly of chunks of ice and dust. The small dark spot on Saturn is the shadow from Saturn's moon Enceladus. This ring is often equipped with vanes and pinholes for use as the alidade of a dioptra (see image). It can be used to measure declination.

Neptune

The Latin word ‘Aurora’ in the left side of the red section means ‘dawn’ or ‘sunrise’. The word ‘Ortus’ above this in the blue section means ‘rising’. The Latin word ‘Occasus’ on the right-hand side of the blue section means ‘sunset’. The word ‘crepusculum’ below this in the red section means ‘twilight’. Discovery and exploration: Saturn’s majestic rings were bright enough to be seen through Galileo Galilei’s telescope in 1610. However, the legendary scientist wasn’t exactly sure what he was looking at, and thought the rings might be moons or arms of some sort. It wasn’t until 1659 that Christiaan Huygens correctly deduced that Saturn had a ring system that encircled the planet.