The Asteroid Belt, also known as the Main Belt, is a three billion cubit-mile asteroid region in the Solar System located between the two planets Mars and Jupiter. It contains a moderate fraction of the asteroids that are found in the Solar System. Not only does this belt contain asteroids, but it also is home to numerous dwarf planets such as Ceres, the dwarf planet closest to our Solar System. This belt is constantly orbiting the Sun, along with the planets.
It is believed, that between the mars and Jupiter, in the early days of the solar system six planetesimals were orbiting. These collided, forming sub-dwarf planets ( like Vesta) and many small asteroids, which ones stay in asteroid families, few of the sub-dwarf planets collided to distruption, or just had an impact, forming other asteroid families, asterioid families formed also by gravitational grouping.
Ceres was probably brought to the asteroid belt after the big six collided, it also formed an asteroid family by gravitational pulls.
Kirkwood gaps were discovered by Daniel Kirkwood in 1857. These are gaps that are caused by asteroids that have the same orbital period, or amount of time taken to orbit the Sun once. When the planet that formed the Asteroid belt was destroyed, some asteroids and fragments were shipped off into deep space, causing these "Kirkwood Gaps".
The composition of the asteroid belt varies depending on the distance at which the asteroids formed from the Sun. These distances bring us three distinct categories of asteroids that exist in this belt: carbonaceous, the most populous, metal-rich asteroids, and silicaceous asteroids.
- Carbonaceous asteroids, also known as C-type asteroids, are the most populous asteroids in the asteroid belt. These asteroids appear much more darker than other asteroids. Carbonaceous asteroids are made up of clay and silicate rocks. These the oldest category of asteroids to exist in our solar system.
- Silicaceous asteroids, also known as S-type asteroids, on the other hand, are made up of silicate rocks and nickel-iron. These are typically lighter than carbonaceous asteroids.
- Metallic asteroids, also known as M-type asteroids, make up the least portion of the asteroid belt. These are mainly made up of mainly nickel-iron. These are the lightest of the asteroids.
Groups of Asteroids
There are asteroids like the cybele a family asteroids or hilda family asteroids, which ones were disturbed by the Jupiter, they eventually became co-orbital with its L3,4, and5 points, meaning, that during the aphelion, the objects are moving together with the L3, 4, or 5. These objects are still in orbital change, they will eventually become Juliter trojans.
Near Earth Asteroids
Though not their formal name, near Earth asteroids follow the orbit of, around, or even travel inside the orbit of the Earth. Mainly referred to as the Apollo, Aten, Amor, and Adams asteroids, these are believed to have future impacts with the Earth within the next hundred thousand to million years. These make orbits within the ranges of Earth and Mars' orbital periods.
Many orter asteroid families exist.
There are bodies located outside of the belt that are shown to have cometary action, or comet-related activity. Main-belt comets are thought to have been a major component in the creation of the Earth's oceans. They are shown to have high amounts of a substance known as deuterium-hydrogen, which cannot be found in regular comets.
Near-Earth objects are asteroids in the Asteroid belt that have collided together and compacted together to form a meteor. This meteor is then sent on a collision-course with Earth and collides with Earth or are disintegrated inside of the atmosphere before it hits the surface.
- Main article: Ceres
Ceres is the only celestial object to be a dwarf planet and an asteroid. In fact, it is the only dwarf planet located in the Asteroid belt. In fact, it maintains hydrostatic equilibrium, which means it is barely massive enough to have even a trace gas in an atmosphere.