through their 166th alphabet! This represents 4,302 objects discovered in that half-month.
To be issued a final number and have its provisional designation taken away, a new asteroid's orbit must be determined closely, and it also must be confirmed that it is not a new sighting of a previously known object.The new asteroid must be observed at opposition (see figure below) four times to make it an official part of the permanent record. In the year 2000, 25,320 minor planets were confirmed and numbered. In 2001, 13,295 were numbered; in 2002, 5,595 were numbered; in 2003, 1,050 were numbered; and in 2004, fewer than 300. The history of minor planet discoveries by year is shown in the figure on page 14. By February 2005, there were 99,906 confirmed and numbered minor planets in total; 108,000 unnumbered objects with fairly well-determined orbits; and 68,000 unnumbered objects with poorly known orbits. There are thought to be millions of asteroids in the solar system, so searchers have a long way to go.
Opposition and Conjunction
Opposition and Conjunction
Opposition and conjunction are the two cases when the Earth, the Sun, and the body in question form a line in space.
The number of minor planet discoveries by year peaked in the year 2000 as interest and technology converged on the problem; further discoveries become more difficult because of small size, dimness, and distance from the Earth. (Data from the IAU: Minor Planet Center)
Final asteroid numbers go in order of confirmation.Thus, Ceres is number 1, and is formally notated 1 Ceres. At the time of this writing, almost 110,000 minor planets have been numbered and had their orbits characterized. Most still have names (about 60 percent at this time) in addition to numbers, but only one has a name but no number: Hermes, whose provisional designation was 1937 UB.
The discoverer of an asteroid has a decade to suggest a name for his or her object once it has its permanent number. The name must be approved by the 11-member "Small Bodies Names Committee." About the first 400 asteroids were named after figures from classical mythology, but since that time, many other categories of names have been used. Asteroids have been named after famous or accomplished people of all stripes, family members, committees, plants, and even machines. Asteroids with special numbers often get special names, as in 1000 Piazzi (the discoverer of the first asteroid), 2000 William Herschel, 3000 Leonardo da Vinci, 4000 Hipparchus, 5000 IAU (the International Astronomical Union), 6000 United Nations, 7000 Marie and Pierre Curie, 8000 Isaac Newton, and 9000 Hal (named
Number of Minor Planet Discoveries by Year
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