Asteroid Belt

Asteroid Belt

Beyond Mars, which marks end of inner solar system, lies a particularly huge space.  On the other side is massive planet Jupiter.  It is in this huge space that Asteroid Belt exists.  Thousands of large and small tumbling rocks is what Asteroid Belt is made up of.  There are four types of asteroids that current Asteroid Belt consists of, carbonaceous asteroids, silicaceous asteroids, metallic asteroids and rare basaltic asteroids.

Carbonaceous asteroids are most common type and make up large percentage of Asteroid Belt and its outer regions.  They are carbon rich and consist of organic compounds.  An interesting article can be found at http://www.psrd.hawaii.edu/April11/amino_acids.html

Silicaceous asteroids are second most common type and make up majority of inner region” of Asteroid Belt.  These types asteroids are mainly composed of iron and magnesium silicates and a very few even show hint of organic compounds.  This tells us that their “materials have been significantly modified from their primordial composition, most likely through melting and reformation”.

Metallic asteroids are third most common type of asteroids.  Their compositions are not fully known, but many consist of nickel, iron and a little stone.  This class of asteroids is not fully understood and it appears there may be several different types.

Basaltic asteroids are considered rare and are mystery in Astrophysics.  They are composed of extrusive volcanic rock and mineral olivine, which is magnesium iron silicate.  If you are interested, you can read more about these mysterious types of asteroids here.

There are main-belt comets that orbit within Asteroid Belt which tend to stay in outer part of belt.  There are also spaces, known as Kirkwood Gaps, cleared where orbital resonances with Jupiter occur.  Orbital Resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on one another.”  The largest gap is at orbital distance which would correspond to period of one third that of Jupiter.

The most massive of all the asteroids is Ceres , comprising over one third of total mass of all of asteroids.  It is considered a dwarf planet, smallest one in our solar system, and only dwarf planet to exist in Asteroid Belt. 

Asteroid Belt is highly unlikely to be remains of a small planet because no sizeable body could ever have formed so close to Jupiter.

Sources:

http://en.wikipedia.org/wiki/Asteroid_belt

http://www.psrd.hawaii.edu/April11/amino_acids.html