Neith is the name given to an object first sighted by Giovanni Cassini, which he believed to be a moon of Venus. It has since been determined that no such moon exists. Giovanni Domenico (Jean-Dominique) Cassini Giovanni Domenico Cassini (June 8, 1625 - September 14, 1712) was an Italian-French astronomer and engineer. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... (*min temperature refers to cloud tops only) Atmospheric characteristics Atmospheric pressure 9. ...

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. Events England, France, Munster and Cologne invade the United Provinces, therefore this name is know as ´het rampjaar´ (the disaster year) in the Netherlands. ... Events The League of Augsburg is founded. ...

The object was seen by many other astronomers over a large period of time: by James Short in 1740, by Andreas Mayer in 1759, by J. L. Legrange in 1761, eighteen observations in 1761, including one in which a small spot was seen following Venus while Venus was in transit across the Sun, eight observations in 1764, and by Christian Horrebow in 1768. An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. ... James Short (June 10, 1710 – June 15, 1768) was an British mathematician, optician and telescope maker. ... Events May 31 - Friedrich II comes to power in Prussia upon the death of his father, Friedrich Wilhelm I. October 20 - Maria Theresia of Austria inherits the Habsburg hereditary dominions (Austria, Bohemia, Hungary and present-day Belgium). ... 1759 was a common year starting on Monday (see link for calendar). ... 1761 was a common year starting on Thursday (see link for calendar). ... Deimos transits the Sun, as seen by Mars Rover Opportunity on March 4, 2004 The word transit has two meanings in astronomy: A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body, as seen by an observer at... The Sun (or Sol) is the star at the center of our Solar system. ... 1768 was a leap year starting on Friday (see link for calendar). ...

Many astronomers, however, failed to find any moon during their observations of Venus, including the great William Herschel in 1768. Sir Wilhelm Friedrich Herschel, FRS (Hanover, November 15, 1738 – August 25, 1822 Slough, then in Buckinghamshire now in Berkshire) was a German-born British astronomer and composer who became famous for discovering the planet Uranus, and made many other astronomical discoveries. ... 1768 was a leap year starting on Friday (see link for calendar). ...

Cassini originally observed the Neith to be one-fourth the diameter of Venus. In 1761, Lagrange announced that Neith's orbital plane was perpendicular to the ecliptic, and in 1777, he estimated its orbital period as eleven days and three hours. He hoped that the moon would be seen during the transit of Venus across the Sun which was to occur on June 1, 1777. 1761 was a common year starting on Thursday (see link for calendar). ... The orbital plane is an astronomical concept. ... The plane of the ecliptic is well seen in this picture from the 1994 lunar prospecting Clementine spacecraft. ... 1777 was a common year starting on Wednesday (see link for calendar). ... June 1 is the 152nd day of the year in the Gregorian calendar (153rd in leap years), with 213 days remaining. ... 1777 was a common year starting on Wednesday (see link for calendar). ...

In 1766, the director of the Vienna observatory speculated that the observations of the moon were optical illusions: the bright image of Venus, he said, was reflected in the eye and back into the telescope, creating a smaller secondary image. 1766 was a common year starting on Wednesday (see link for calendar). ... An optical illusion is any illusion that deceives the human visual system into perceiving something that is not present or incorrectly perceiving what is present. ... This article needs to be cleaned up to conform to a higher standard of quality. ... 50 cm refracting telescope at Nice Observatory. ...

In 1884, M. Hozeau, 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. Hozeau was also the first to give the object the name Neith, after an Egyptian goddess. 1884 is a leap year starting on Tuesday (click on link to calendar). ...

The Belgian Academy of Sciences published a paper which studied each reported sighting of Neith in 1887. 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. 1887 is a common year starting on Saturday (click on link for calendar). ... Chi Orionis is a star system about 32 light years away from Earth. ...

External Links

• Neith, the Moon of Venus