Meteorites

Definition, sources, types, and its dangers, and the best known, and most famous craters.

Introduction to meteorites

Meteorites are objects belong to the solar array, which is the waste that remained in the space of the solar system after the planets form, and even called these objects meteors Meteorite they must hit the surface of the planets or moons, if we look, for example, to the surface of the moon, we saw hundreds of craters caused by the collision of meteorites in the early stages The first of its composition, as well as for the surfaces of other rocky planets like Mars and Mercury. 
 

Meteorites pose a real threat to Earth, but thanks to God and thanks to the Earth's atmosphere to turn these meteorites meteors Meteor where burn and fade before it reaches the Earth's surface.

When approaching rock masses of different and that swim in the space of the Earth, the Earth's gravity affect them leading to attract it toward the ground, and when it enters the Earth's atmosphere and come into contact with atoms of elements carbonated, this leads to a rise in temperature to more than 2,500 degrees Celsius, either to burn and fade, and this is known by meteors Meteor], or they are not a big fade college atmosphere, but part of it up to the surface of the earth, and this is what is known as [meteorites meteorite] and may explode in the atmosphere and flaking pieces on the ground.

Up to Earth from space daily millions of rock masses, but thankfully most of these rock masses just meteors do not affect the Earth, but what is a meteor Fddh few of them.

And increasing the weight of the earth annually from 0.7 to 7 kg per square kilometer per year because of the fall of meteorites and comets ashes on them.

Cutting meteor scattered on the earth
 

Speed ​​and size of meteors and meteorites

When you reach the meteor to Earth, the speed is between 10-80 km / sec, and begin to glow when you become an altitude of 100 km above the ground, almost have evaporated completely when you become an altitude of 48-80 km above the ground almost, and range in size Shehab often between a grain of sand to a pea, and when it appears meteor is a bright light, that is called by the fireball fireball], which is characterized as leaves behind a trail of dust and clear.
As for the speed of the meteors near the speed of meteors the size shall be larger than the size of meteors, it is between several feet to several miles.

Sources of meteorites

1) asteroid belt

It is considered one of the most important sources of meteorites that have hit the ground, and there is nothing between the orbits of Mars and Jupiter vast distance contain many rock masses that have sizes between the size of gravel to several hundred miles wide, and the mass of all these rocks does not exceed 5% of the mass Moon, and the so-called big ones by asteroids, and from time to time off some rock masses of orbit and enter Earth's atmosphere.

2) objects resulting from the collision of an object to one of the planets

and these objects lounging continuously in the solar system, and could pose a threat to their collision with us.

3) Ciobr Belt

And includes a large number of objects, but the danger is less due to the presence of Jupiter with a terrible gravity, which reduces the possibility of arriving to us, and the belt is located Ciobr after the orbit of the planet Neptune

 

Installation of meteorites

According to scientists for analysis of meteorites that fell to Earth, the meteorites are divided into three sections:
The first iron meteorites, consisting mostly of iron, nickel and cobalt.
II: rocky meteorites, similar in general for the installation of the rocks, but the intensity is higher than the density of natural stones.
Third: rocky iron meteorites

Dangers of meteorites

Cause large meteorites Bodharara enormous on the planet and life on it. Vastdam large meteor land may lead to the generation of nozzle with a diameter of 10-20 twice the diameter of the meteorite , where the meteorite collision that leads to generate power equivalent to the explosion of a nuclear bomb from one to thousands of nuclear bombs , which vary the force generated by the collision because of the size and speed of the meteor For example : the power of a meteor explosion in Siberia in 1908, 1000 times more powerful than the Hiroshima bomb .One of the clearest examples of the seriousness of the meteorites that put scientists about the cause of the extinction of the dinosaurs on Earth. Before 65 million years the dinosaurs are objects dominant on the planet not competing on that one , but the offense heavenly hit the planet and annihilated the equivalent of three-quarters of the life that was on the planet , including the dinosaurs , and did not die so the collision died, the effects of this collision and perhaps the most prominent it was cold the ice , where the land covered dense dust cloud led to the Gulf ice age hemisphere ice , and after this long winter has not left any trace of dinosaurs and other mammals were able to evolve and continue after the extinction of the dinosaurs .

Meteorite craters and meteorites dangers

Geologists discovered so far on the ground about 175 hole caused by stones meteorite , and ranges in width from a hundred miles and several hundred feet , is certain that the number of craters much larger , but since that two-thirds of the Earth is covered by water the probability of the occurrence of a meteor in the water is 3 to 4 , and also may be weathering and erosion and erosion factors enough to hide the effects of a large meteorite strikes that occurred in ancient times , or perhaps that the hole had filled with water with time.
Months of craters discovered on the surface of the earthNozzle Deep Bay, which is located in an area Saskachwan in Canada , and this orifice circular with a diameter of about 13 kilometers, and reaches a depth of more than 220 meters , which is a part of the lake is more spacious ones and irregular in shape , and scientists estimate the age of the crater about 99 million years .Vohta Clearwater clear water, located in Quebec , Canada , and two double-barreled Nizquitin Cklta together since about 290 million years , the impact of the blow meteorite double, and the diameter of the crater meteorite large about 32 km , while the nozzle Minor amounts to a diameter of about 22 km , has turned Alfohtan Lakertan to large .Famous Barringer crater in Arizona, U.S. , and a width of more than a mile and a depth of over 175 meters. This crater was formed about 50,000 years ago when an iron meteorite collision diameter of about 50 meters long and weighed the equivalent of a few million tons , and this is the nozzle orifices of the very rare and that still maintain their shape.Nozzle and Wolf Creek , which is located in the desert areas in the north of Australia , which is also from nozzles of the very few that still maintain their shape. The age of the crater is about 300,000 years old , and a diameter of 880 meters , and the depth amounts to about 60 meters , was discovered in 1947 .Bustomtoa nozzle , located in Ghana in Africa , and a diameter of 10.5 km and age more than 1.3 million years , and this crater filled with water almost entirely , which is called Lake Bustomtoa .Manicoagan nozzle , which is located in Quebec , Canada , was formed nearly 212 million years , and this has turned into the crater lake is now covered with ice diameter of about 70 km, and show where the outer ring of rocks surrounding Balvohh . These rocks show clear signs of melting due to the violent collision , it is believed that the true diameter of the nozzle was only 100 km, but adjusted by factors of climate and erosion.

the most famous meteorites that hit the Earth

June 30, 1908 , in the early morning broke a meteorite Earth's atmosphere over Siberia , and the speed is estimated at about 54,000 km / h , according to eyewitnesses have seen a meteor 400 km from the site , and it was in the form of a big ball inflamed, accompanied by the sound of boisterous strong , before colliding with the Earth at about 6 km rise , burst the meteor over the River Tunguska Tunguska explosion terrible sent through shock waves through the air 's reputation both in the world at that time , and the resulting explosion to clear the forest there are hundreds of miles away , and the uprooting of more than 60 million trees pine area estimated at 2150 square kilometers . It was said that the blast was 1000 times stronger than the Hiroshima bomb .

 

Hoba meteorite iron, and now exists in South Africa, which is the largest piece of the meteorite has been discovered so far, and weighs more than 60 tons, the scientists estimated that the meteorite fall by more than 80,000 years.

 

Meteorite ALH84001, which I found scientist Alberta SCORE in 1984 in the fields of Allan Hills in Antarctica, and deliver a meteorite worldwide attention because it is a great Martian meteorite, which makes the study may lead to knowledge of life on Mars are explained. This meteorite has fallen on the ground since about 13,000 years ago.