Asteroid
Synonyms: planetoid (literally: planet-like); minor planet[1].
One of the smaller celestial bodies - largely made up of rocky material - that orbit the Sun in a similar way as the more well-known planets.
Astronomy
The asteroids have diameters which range from a few metres up to 1 000 Km. The first asteroids, which remain the most widely known, were discovered at the beginning of the 19th century: Ceres, Pallas, Juno and Vesta.
Numerous asteroids have orbits that lie between Mars and Jupiter, in the so-called asteroid belt. Ceres, Pallas and Vesta are the three largest asteroids in the asteroid belt. Also, Juno is in the asteroid belt.
There is another belt of asteroids in the solar system, the so-called Kuiper Belt which lies beyond the orbits of Neptune and Pluto. The Kuiper Belt is thought to contain a much greater number of asteroids than the asteroid belt. The present consensus is that the Kuiper Belt is made up of matter which was prevented from condensing into one planet - in this case by the pull of Neptune's gravitational field. Pluto has recently been classified as the largest celestial body belonging to the Kuiper Belt and reclassified as a dwarf planet.
The so-called centaurs have also been classified as asteroids. Their orbits around the Sun lie between Jupiter and Neptune, and they would appear to function as a "bridge between asteroids and comets, or/and the ancestors of comets." The most known centaur is Chiron.
Astrology
For a long time the asteroids weren't considered to be significant factors in astrology, one reason being their small size. In addition, it has been difficult and controversial trying to connect them to any particular signs of the zodiac. However, interest in the asteroids has been growing since the 1980s, especially in Ceres, Pallas, Juno and Vesta. Some consider them to embody feminine counterbalances to the main planets which have been named predominantly after masculine gods of antiquity. It is conspicuous that three of the names (Ceres, Juno and Vesta) have their origins in Roman tradition, and one (Pallas) in Greek.
Also Chiron is considered by some contemporary astrologers.
Notes
- ↑ The term minor planet, originally used to describe these celestial bodies, show that astronomers were originally reluctant to put them on an equal footing with the major planets in our solar system. In fact, it is not really possible to make a clear distinction between the minor and the (major) planets. On this subject Dieter Koch, who is an advocate of the term minor planet, writes:
"It is actually difficult to say why these celestial bodies should only be 'planet-like' and not planets. Making this distinction based on size is untenable... then again, the expression 'star-like' seems in any case to call for the complementary term 'planet'."
In regard to the argument over size, Koch points to the fact that Pluto's diameter is only 2 320 Km.
