An asteroid is a rocky body in space that is not a planet, moon, nor comet. The word asteroid is Greek for "star-like," which is actually inaccurate in terms of the modern meaning of the word star. The International Astronomical Union uses the term minor planet, while some others prefer the term planetoid, meaning "planet-like."
Size and Composition
Not much is known for certain regarding asteroid composition except through meteorite analysis and old spectroscopic surveys.
The major asteroids are the largest asteroids known and are among the first to be discovered. Ceres, with a diameter of 952 km, was the largest known asteroid until its reclassification as a dwarf planet in 2006. After the reclassification, the largest known asteroid is 2 Pallas, which has a diameter of 531 km. The major-asteroid group also includes 3 Juno, 4 Vesta, 433 Eros, and 1036 Ganymed (not to be confused with Ganymede, moon of Jupiter).
The main categories into which the smaller asteroids are currently classified are:
The majority of asteroids are classified as being C-type, primarily by spectroscopic analysis. But spectroscopes are not necessarily reliable in determining the composition of asteroids, and the actual composition of asteroids is under debate.
The greatest collection of asteroids in the solar system is the main asteroid belt between the orbits of Mars and Jupiter. The total estimated mass of all the objects in the belt is 4% of the mass of Earth’s moon, and this is scattered over a fairly wide area, contrary to many motion pictures which incorporate thickly inhabited asteroid belt scenes. The recent reclassification of Ceres as a dwarf planet reduces the mass of the remaining asteroids to less than 3% of the moon's mass.
Evolutionists generally believe that the asteroid belt is a collection of leftovers from the solar system’s formation, pieces which were not able to collect and form into a planet. A currently less popular idea is that the belt is a leftover of a destroyed planet. But any such planet would have been less massive than either Earth's moon or any of the moons of dwarf planet size that orbit the gas giants.
Russell Humphreys  that the Moon suffered two distinct episodes of bombardment, one occurring three centuries after the fall of man and the other occurring within a century of the global flood. In theory either event could be related to the formation of the asteroid belt.
The most coherent creationist model offered to date for the origin of the asteroid belt derives from the hydroplate theory of Walt Brown. Specifically, Dr. Brown suggests that asteroids, meteoroids, and comets all came from the quantities of rock, mud, and water that were ejected into space during the breakout of Earth's once-subterranean ocean.
- Main Article: Dinosaur extinction
An asteroid impact is also used by evolutionists as an explanation for the extinction of the dinosaurs, as well as a number of contemporaneous life forms. However, there is no solid evidence for such a scenario, and it has been pointed out that many types of life forms that would have been sensitive to an asteroid impact of sufficient magnitude to cause mass extinction show no signs of having experienced such an event.
Nearly every planet in the solar system violates the nebula hypothesis in one manner or another. For example, Mercury is too dense, Venus rotates retrograde, Earth's own Moon is too large, Uranus appears to roll on its side, and Uranus' moon Miranda has the most irregular surface yet known. In every case, astronomers invoke, or have invoked, a giant impact to explain the departure from the nebula model. But some of these hypothetical objects are as large as Mars, and Mars has ten percent of the mass of Earth and hence 8 to 9 times the mass of the Moon. The dwarf planet Ceres, the largest object in the asteroid belt, could not have produced any of the effects that astronomers have attributed to these impacting objects. Wherever such objects came from, they could not have come from the asteroid belt. Nor could any object combining the masses of all the asteroids do anything like this.
- Moore, Patrick; Hunt, Gary (1983). Atlas of the Solar System. Chicago: Rand McNally & Company. p. 243. ISBN 0-528-81122-3.
- http://creation.com/images/pdfs/tj/j28_3/j28_3_51-60.pdf Magnetized moon rocks shed light on Precambrian mystery
- Humphreys, D. R. "The Creation of Planetary Magnetic Fields." Creation Research Society Quarterly 21(3), December 1984. Accessed April 29, 2008.
- Brown, Walt. "The Origin of Asteroids and Meteoroids." In the Beginning: Compelling Evidence for Creation and the Flood. May 28, 2008. Accessed June 2, 2008.
- Psarris, Spike. Our Created Solar System Seattle Creation Conference, 2006.
- Asteroid by Wikipedia
- Asteroid Fact Sheet NASA
- Did a meteor wipe out the dinosaurs? by Answers in Genesis