The solar system - the Oort Cloud

 The Oort Cloud is a collection of icy comets far beyond Pluto. It is the farthest place from the Sun in the Solar System. The Oort Cloud marks the end of the Solar System becuase beyond it the Suns gravity is to weak to hold anything so it will be pulled away from the Sun. It surrounds the planets like a cage. The Oort Cloud is about 8 million million kilometers in diamater.

Comets heavenly Oort Cloud is a huge spherical cloud surrounding the solar system and extends for a distance of three light-years away, and is located about 30 trillion miles from the sun, this vast distance is on the edge of the attractiveness of the sun.

Within this cloud there comets that cross billions of kilometers, and these objects associated with attractive weak sun, and can affect the Mdarathm stars or any other force and that could change the Mdarathm and Msarthm with ease, this force or those send them to the inner solar system or to outer space remote , this is the reality of comets on the outer edge of the Oort Cloud.

Installation Cloud believed that include center heavy proportionately and which may extend near the district level virtual sun and filled the external borders gradually composed steady state, one-sixth of objects Cloud's about six trillion body or comet snowy almost resides in the outer region and the rest Vtquba at the center relatively dense.

There is concern from crossing another star through the Oort Cloud or even near - since this impacts on clouds giant extending this power, that the cloud giant largely her intensity enormous more than the sun, where the accumulation gathered hydrogen cold is the appropriate place for the birth of stars and systems its like the solar system, but this rarely happens all around 300 to 500 million years ago, but when this happens encounters can restore the distribution of comets strongly through the cloud.

Power tide affecting the Oort cloud generated by stars of the Milky Way and some influence from the center of the galaxy and the tide caused by the sun and comets that are at different distances from the massive amounts of the substance, and force the comets of this tide greatest concern of the passage of stars near the cloud, and comets that are beyond 200,000 astronomical units easily lost in deep space, this effect contributes to the stability of the external case of comets randomly distributed away from the virtual circle of the sun.

The total mass of comets in the Oort cloud is believed to be 40 times the mass of Earth, this issue makes us believe that they formed and grew up in a different place far from us, this illustrates the diversity of the structure observed in comets.

The Oort cloud is a source of comets with orbits long are also likely to be middle of comets with the highest propensity which has attracted in the shortest orbits of the planets, such as Halley's Comet and Comet Swift Total. And comets can change and modify their orbits also because of the flow and the emission of gas and dust from on snow سطحهم whenever they approached the sun. It can also lose comets Msartha and lost in space and some of them have orbits widely than 200 years to once every million years or more. As comets entering the solar system for the first time have come from an average distance of 44,000 astronomical units or more.
Comets with long periods can appear at any time and come from any quarter, and comets bright can be visible usually every 5 to 10 years, and two comets cloud Aurat two guilty Hiakotak and guilty Hull Bob, either guilty Hiakotak was average in size, but getting closer to a distance of 15,000,000 miles from Earth, which make it appear nicely.

On the contrary, the comet Hale Bob has been guilty of a large and unusually dynamic, ten times the distance that will be after this comet from the sun, making it appear quite bright however, did not come close from the ground more than 197,000,000 kilometers.


Study Oort cloud gave an explanation of the questions the old "What heya comets, where it comes from," in 1950 concluded astronomical Dutch presence cloud of some evidence of physical comets long period that enter our solar system, this astronomer Dutch is interpreted turnover Milky Way in 1920 and interpreted the diversity Madart comets with 19-round well-defined and managed to find out where it comes from these comets, and supported the data gathered by his explanations, to establish and expand our knowledge of the Oort cloud.

Small bodies are believed to be the primordial building blocks of the planets. The principal reservoirs of the small bodies are the asteroids (main-belt and near-Earth), the comets, the Centaurs, the Kuiper belt objects and the comets of the Oort Cloud. Small bodies are especially important in planetary science for two reasons. First, most small bodies have escaped wholesale melting or other severe forms of thermal processing and thus preserve chemical compositions closer to the initial ones. [In fact, many small bodies (e.g. the comets) formed and remained so cold over cosmic time that they retain the volatile ices from which they formed]. Second, the small bodies are very numerous compared to the major planets. They make excellent dynamical tracers and allow detailed models of the origin and evolution of the solar system to be tested.

Studies

Near-Earth asteroids represent an impact threat but also an opportunity to conduct investigations from the Earth that are impossible on more distant targets.  Radar studies and optical lightcurves show that many near-Earth asteroids are binaries, raising interesting questions about their origin and survival. (Jean-Luc Margot, Michael Busch, Julia Fang, Shantanu Naidu)
Some asteroids in the main-belt between Mars and Jupiter have recently been found to show comet-like behavior, ejecting dust from their surfaces and sporting cometary comae and tails.  Some of these appear to be activated by the sublimation of water ice (i.e. they are compositionally comets).  These objects were either formed in-place or, perhaps, captured from the Kuiper belt long ago.  They may represent survivors of a now-depleted population that could have supplied some of the Earth’s water. (David Jewitt)
Other active asteroids are produced by collisions which, in the main-belt, occur with relative speeds of several kilometers per second and are therefore explosive (NASA movie)  Being able to observe on-going collisions opens the door to the study of hypervelocity impact in the real world, and should have important ramifications for dust production in the solar system and in the debris disks of other stars. (David Jewitt, Michal Drahus)
Although quite large, asteroid 4 Vesta is another “small body” asteroid, made special by the visit of the ion-powered DAWN spacecraft.  A UCLA investigator leads the mission, while others explore the nature of the surface from high resolution images. (Chris Russell, Jennifer Scully)
Beyond Neptune lies the Kuiper belt, a repository of primordial solar system matter that feeds a steady stream of comets into the inner solar system.  On-going investigations study the comets and the Kuiper belt objects themselves. (David Jewitt, Aurelie Guilbert-Lepoutre, Michal Drahus, Hilke Schlichting, Rachel Stevenson)