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Neith is a hypothetical natural satellite of Venus reportedly sighted by Giovanni Cassini in 1672 and by several other astronomers in following years. It was 'observed' up to 30 times by astronomers until 1770, when there were no new sightings and it was not found during the transit of Venus in 1761 and 1769. [1] [2]
In 1672, Giovanni Cassini found a small object close to Venus. He did not take great note of his observation, but when he saw it again in 1686, he made a formal announcement of a possible moon of Venus. [3] The object was seen by many other astronomers over a large period of time: by James Short in 1740, [4] by Andreas Mayer in 1759, [4] by Louis Lagrange in 1761, [5] another eighteen observations in 1761, including one in which a small spot was seen following Venus while the planet was in a transit across the Sun, eight observations in 1764, and by Christian Horrebow in 1768. [6]
| Year | City | Person | Number of sightings |
|---|---|---|---|
| 1645 | Naples | Francesco Fontana | 3 [4] |
| 1646 | Naples | Francesco Fontana | 1 [4] |
| 1672 | Paris | Giovanni Domenico Cassini | 1 [4] |
| 1686 | Paris | Giovanni Domenico Cassini | 1 [4] |
| 1740 | London | James Short | 1 [4] |
| 1759 | Greifswald | Andreas Mayer | 1 [4] |
| 1761 | Marseilles | Joseph Lagrange | 3 |
| 1761 | Limoges | Jacques Montaingne | 4 |
| 1761 | St. Neots | unknown | 1 |
| 1761 | Greifswald | Friedrich Artzt | 1 |
| 1761 | Krefeld | Abraham Scheuten | 2 |
| 1761 | Copenhagen | Peter Roedkiær | 8 |
| 1764 | Copenhagen | Peter Roedkiær | 2 |
| 1764 | Copenhagen | Christian Horrebow and others | 3 |
| 1764 | Auxerre | Marian | 3 |
| 1768 | Copenhagen | Christian Horrebow | 1 |
Many astronomers failed to find any moon during their observations of Venus, including William Herschel in 1768[ citation needed ]. Cassini originally observed Neith to be one-fourth the diameter of Venus. In 1761, Lagrange announced that Neith's orbital plane was perpendicular to the ecliptic. [5] That same year, however, mathematician Jean le Rond d'Alembert wrote to Voltaire that Neith had "declined to follow his mistress during her passage over the sun", questioning whether Venus truly had a moon. [7] In 1766, the director of the Vienna Observatory speculated that the observations of the moon were optical illusions. He said: "the bright image of Venus was reflected in the eye and back into the telescope, creating a smaller secondary image."[ citation needed ] In 1777, J.H. Lambert estimated its orbital period as eleven days and three hours.[ citation needed ]
In 1884, Jean-Charles Houzeau, the former director of the Royal Observatory of Brussels suggested that the "moon" was actually a planet which orbited the Sun every 283 days. Such a planet would be in conjunction with Venus every 1080 days, which fit with the recorded observations. Houzeau was also the first to give the object the name Neith, after an Egyptian goddess.[ citation needed ]
The Belgian Academy of Sciences published a paper in 1887 which studied each reported sighting of Neith. Ultimately, they determined that most of the sightings could be explained by stars which had been in the vicinity of Venus, including Chi Orionis, M Tauri, 71 Orionis, Nu Geminorum and Theta Librae.[ citation needed ]
The history of astronomy focuses on the contributions civilizations have made to further their understanding of the universe beyond earth's atmosphere. Astronomy is one of the oldest natural sciences, achieving a high level of success in the second half of the first millennium. Astronomy has origins in the religious, mythological, cosmological, calendrical, and astrological beliefs and practices of prehistory. Early astronomical records date back to the Babylonians around 1000 BCE. There is also astronomical evidence of interest from early Chinese, Central American and North European cultures.
Vulcan was a proposed planet that some pre-20th century astronomers thought existed in an orbit between Mercury and the Sun. Speculation about, and even purported observations of, intermercurial bodies or planets date back to the beginning of the 17th century. The case for their probable existence was bolstered by the support of the French mathematician Urbain Le Verrier, who had predicted the existence of Neptune using disturbances in the orbit of Uranus. By 1859 he had confirmed unexplained peculiarities in Mercury's orbit and predicted that they had to be the result of the gravitational influence of another unknown nearby planet or series of asteroids. A French amateur astronomer's report that he had observed an object passing in front of the Sun that same year led Le Verrier to announce that the long sought after planet, which he gave the name Vulcan, had been discovered at last.
A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body. Natural satellites are colloquially referred to as moons, a derivation from the Moon of Earth.
The following is a timeline of Solar System astronomy and science. It includes the advances in the knowledge of the Earth at planetary scale, as part of it.
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Skathi, also named Saturn XXVII and originally spelled Skadi, is a natural satellite of the planet Saturn. Skathi is one of Saturn's irregular moons, in its Norse group of satellites. It was discovered on September 23, 2000, by a team of astronomers led by Brett Gladman. The team announced their discovery on December 7, 2000, along with seven other satellites of Saturn, namely; Tarvos, Ijiraq, Thrymr, Siarnaq, Mundilfari, Erriapus, and Suttungr. The moon was named after Skaði, a figure in Norse mythology, as part of an effort to diversify the largely Greek and Roman names of astronomical objects.
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Kordylewski clouds, also named ghost moons, are concentrations of dust that exist at the L4 and L5 Lagrangian points of the Earth–Moon system. They were first reported by Polish astronomer Kazimierz Kordylewski in the 1960s, and confirmed to exist by the Royal Astronomical Society in October 2018.
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524522 Zoozve (; provisional designation 2002 VE68) is a sub-kilometer sized asteroid and temporary quasi-satellite of Venus. Discovered in 2002, it was the first such object to be discovered around a major planet in the Solar System. It has nearly the same orbital period around the Sun that Venus does. In a frame of reference rotating with Venus, it appears to travel around it during one Venerean year, but it orbits the Sun, not Venus.
GiovanniDomenico Cassini, also known as Jean-Dominique Cassini was an Italian mathematician, astronomer, astrologer and engineer. Cassini was born in Perinaldo, near Imperia, at that time in the County of Nice, part of the Savoyard state. Cassini is known for his work on astronomy and engineering. He discovered four satellites of Saturn and noted the division of its rings; the Cassini Division was named after him. Giovanni Domenico Cassini was also the first of his family to begin work on the project of creating a topographic map of France. In addition, Cassini also created the first scientific map of the moon.
Phaeton is a hypothetical planet hypothesized by the Titius–Bode law to have existed between the orbits of Mars and Jupiter, the destruction of which supposedly led to the formation of the asteroid belt. The hypothetical planet was named for Phaethon, the son of the sun god Helios in Greek mythology, who attempted to drive his father's solar chariot for a day with disastrous results and was ultimately destroyed by Zeus.
Claims of the existence of other moons of Earth—that is, of one or more natural satellites with relatively stable orbits of Earth, other than the Moon—have existed for some time. Several candidates have been proposed, but none have been confirmed. Since the 19th century, scientists have made genuine searches for more moons, but the possibility has also been the subject of a number of dubious non-scientific speculations as well as a number of likely hoaxes.
Discovery and exploration of the Solar System is observation, visitation, and increase in knowledge and understanding of Earth's "cosmic neighborhood". This includes the Sun, Earth and the Moon, the major planets Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune, their satellites, as well as smaller bodies including comets, asteroids, and dust.
The following outline is provided as an overview of and topical guide to the Solar System:
The following outline is provided as an overview of and topical guide to Venus:
In astronomy, planetary transits and occultations occur when a planet passes in front of another object, as seen by an observer. The occulted object may be a distant star, but in rare cases it may be another planet, in which case the event is called a mutual planetary occultation or mutual planetary transit, depending on the relative apparent diameters of the objects.
