Asteroids, minor planets or planetoids are referred as smaler objects, which move on kepler rule orbits mostly between Mars and Jupiter’s orbit around the sun,and are larger than meteoroids, but smaller than dwarf planets, and do not outgas unlike comets near the Sun.
1801 the astronomer and theologian Giuseppe Piazzi discovered by chance the first planetoid. Unfortunately Piazzi became ill and was not able to continue his observations. Until the publication of his observations passed much time. During this time the celestial body has moved on towards the sun and could not immediately be found again. Heinrich Wilhelm Olbers discovered the object again on 31 December 1801 which was then named Ceres.
In 1802 Olbers discovered another celestial body, which he called Pallas. In 1803 Juno was discovered and in 1807 Vesta. Until the discovery of the fifth asteroid, Astraea in 1845, passed 38 years. Some hundred more were found until the end of the century. After 1890, the introduction of photography in astronomy brought significant advances. The asteroid, which were laboriously found by comparing telescopic observations using sky maps, could now be found on the photographic plates by light trails. The higher sensitivity to light of the photographic emulsions compared to the human eye made it possible to detect extremely faint objects.
The names of the asteroids are composed of a prefix number and a name. In former times the number indicated the sequence of the discovery of the celestial body. Today it is just a number, which is only awarded when the orbit of the asteroid is secured and the object is always retrievable.
Piazzi gave the first from him discovered celestial body the name “Ceres Ferdinandea”. The Roman goddess Ceres is the patroness of the island Sicily. With the second name Piazzi wanted to honor King Ferdinand IV., the ruler of Italy and Sicily. This displeased the international research community and the second name was dropped. The official name of the asteroid is therefore (1) Ceres. For further discoveries, the nomenclature has been retained and the asteroids were named after Roman and Greek goddesses; These were (2) Pallas, (3) Juno, (4) Vesta, (5) Astraea, (6) Hebe, and so on.
As more and more asteroids were discovered, astronomers run out of ancient deities. So asteroids were named among others after the wives of the discoverer, named in honor of historical figures or public figures, cities and fairytale characters. Examples include the asteroid (21) Lutetia, (216) Cleopatra (719) Albert, (1773) Rumpelstiltskin (5535) Anne Frank, (17744) Jodiefoster. In addition to names from the Greek and Roman mythology also names of deities from other cultures are used, particularly for newly discovered large objects, such as (20000) Varuna, (50000) Quaoar and (90377) Sedna. Moons of asteroids donīt get a permanent number next to their name and are not considered as asteroids or small bodies, as they do not orbit the Sun on their own.
Until now more than 1,000,000 asteroids are known in the solar system, but the actual number is probably much higher. However, only very few of them have more than a few kilometers in diameter. Large asteroids are (2) Pallas, (3) Juno, (4) Vesta, (5) Astraea, (6) Hebe, (7) Iris, (10) Hygeia and (15) Eunomia.