Solar System

Are small objects believed to have left since the beginning of the formation of the solar system 4.6 billion years ago, a rocky objects with round shapes or irregular shapes, spanning a distance of several hundred kilometers, but most small-sized enterprises.

The asteroid belt is located in an area between Mars and Jupiter. The so-called main belt to distinguish it from Keiber Kuiper belt and the Oort Cloud. The dwarf planet Ceres Ceres is the largest objects in this belt where the mass alone almost 25% of the mass of the belt, and asteroids are the Palace and Hegih and Vista as well as Sears largest blocs, accounting for more than half a block this belt. Range belt asteroids sizes from Sears Ceres as the largest size the offense to grains such as dust particles.

And take most of the asteroids irregular shapes, but the wedding-cake takes almost spherical shape, fill drilling in most cases. The asteroid rotates in Ahljugih orbits around the sun, as it revolves around itself, irregular cycles.

Ranking asteroids

Asteroids are classified into three categories according to installation Alkwykab: 

Type Si (C) a reference to the word Carbonaceous means kindled.

This type of asteroids is the most common species, and is likely to consist of dirt and silicate rocks and these types seem dark. It is the most ancient objects in our solar system.
 
Type S (S), a reference to the word Silicaceous mean Celikati.

This type consists of asteroids from stones silicate nickel and iron.
 
Type M (M) a reference to the word metal Metallic and mean.

And this type asteroids composed of iron, nickel


The reason is a difference asteroids structures to dimension and nature تشكلهم away or close to the sun. Some asteroids and faced high temperatures after تشكلهم and partially melted and the concentration of iron in the heart of the asteroid, forcing lava to go out to the surface. Such an asteroid is a witness to what happened at the beginning of the solar system and asteroid Vista is the best evidence remains to this day.

Theories are asteroids

Even now there are more than half a million asteroid known, and still the numbers were far more Mmon widely in an area of ​​about one million to three million miles, and is found in a location within the solar system so that it looks as if there is a jump between planets. Scientists believe that this debris may be the remains of a planet which crashed early in the beginning of the formation of the solar system. As was explained Heinrich Albrs Heinrich Olbers in 1802 that this may constitute a belt by the explosion of an ancient planet, perhaps as a result of an internal explosion or how much emotion and a huge volume of comets millions of years ago. But the modern interpretation of the scientists were doing wrong or that it did not happen as the planet crash requires a huge amount of energy, in addition to the low total mass of the belt, which is less than the mass of Earth's moon, which boosted rejected the theory of Heinrich.
Scientists now believe that these asteroids floating in orbit has been formed individual was not a planet at all, but occurred over millions of years and merged some asteroids to each other as a result of collisions with each other. Also believes that the dwarf planets within this belt has been formed in the same way. Has been given several thousand of these asteroids larger names, table below shows some of the names and attributes of some of these asteroids.


Near-Earth asteroids
Where might constitute such objects great danger we if the intersected those ORBITALS at the same time with the Earth's orbit and used telescopes visual addition to the radar in detecting and monitoring any potential dangers, but the chances of a collision asteroid is a very low probability, but some of them approaching actually from the ground , such as Harms Hermes (approaching a distance of 777.000 kilometers).


Space missions to study asteroids
Sent NASA several missions to follow up and study these asteroids. Vehicle Galileo satellite flew near the asteroid Kaspra Gaspra in 1991 and Ida Ida in 1993, and the task of studying the comet yoke - Schoomaker NEAR-Shoemaker has to pass through and study the asteroid Mathilde Mathilde and Eros Eros, and the task of Deep Space One (Deep Space 1) and Star Dust Stardust Both have studied a number of asteroids.

In 2005, the Japanese Hayabusa spacecraft landing on a near-Earth asteroid called Atocaua Itokawa to collect samples. The mission successfully returned to Earth in June 2010, Scientists are now studying those molecules that have been collected, and it was this mission is the first of its kind in the landing and collect samples and take-off from the surface of an asteroid