In the following tables, planetary satellites are indicated in bold type (e.g. Moon) while planets, major or minor, which directly circle the Sun are in italic type (e.g. Earth). The tables are sorted by publication/announcement date. Dates are annotated with the following symbols:
i: for date of first imaging (photography, etc.);
o: for date of first human visual observation, either through telescope or on photographic plate (the true "discovery" moment);
p: for date of announcement or publication.
*Note: Marked moons had complicated discoveries. Several moons took several years to be confirmed, and in several cases were actually lost and rediscovered. Others were found in Voyager photographs years after they were taken.
Contents
1Color code
2Prehistory
317th century
418th century
519th century
620th century
721st century
8See also
9External links
Color code
The planets and their natural satellites are marked in the following colors:
In the Ptolemaic system, the Earth was believed to be at the center of the cosmos. Seven planets were placed in orbit around it in an order of increasing distance from the Earth, first established by the Greek Stoics: the Moon, Mercury, Venus, the Sun, Mars, Jupiter and Saturn. This list included two objects, the Sun and the Moon, which are no longer considered to be planets; it also excluded the Earth.
In Nicolaus Copernicus' heliocentric system (De Revolutionibus Orbium Coelestium, 1543) the Earth came to be considered a planet revolving with the other planets around the Sun, in the following order of distance from the Sun: Mercury, Venus, Earth, Mars, Jupiter, and Saturn. The Sun, now situated near the center of revolution, was no longer considered a planet.
In the Copernican system, the Moon was considered to be no longer a planet but a natural satellite of the Earth, and was the only body in that system whose revolution was not centered on the Sun.
Galileo, Sidereus Nuncius, [1]. The Galilean moons. Note: One of the moons may have been recorded by the ChineseastronomerGan De in 364 BC. The Galilean satellites were the first celestial objects that were confirmed to orbit an object other than the Earth.
Huygens, [2]. Huygens first "published" his discovery as an anagram, sent out on June 13, 1655; later published in pamphlet form as De Saturni luna Observatio Nova and in full in Systema Saturnium (July 1659).
In his work Kosmotheôros (published posthumously in 1698), Christiaan Huygens relates "Jupiter you see has his four, and Saturn his five Moons about him, all plac’d in their Orbits."
Giuseppe Piazzi. He first announced his discovery on January 24, 1801, in letters to fellow astronomers. The first formal publication was the September 1801 issue of the Monatliche Correspondenz.
