The etymological origin of crater is found in a Greek word that later derived into the Latin crater (translatable as "cup" ). In the broadest sense , a crater is a depression or concavity that is usually circular in shape.
In general, the notion refers specifically to the topographic depression that is generated by the explosion of a volcano , through which lava, ash, smoke and other substances or particles can emerge.
Volcanic activity produces this type of craters that are usually located at the top of the volcano and function as its “mouth” . There are volcanoes that have a main crater and other secondary ones.
Craters, on the other hand, can be produced by the impact caused by a meteorite when it falls on the Earth's surface. Depending on the mass , speed and kinetic energy of the meteorite, the resulting crater will be more or less large.
An example of these craters is the Vredefort Crater in South Africa . It is believed to have occurred more than 2 billion years ago, making it the oldest crater on our planet among all those that are visible.
Craters are also found on other planets beyond Earth , and even on satellites such as the Moon . Craters have been detected on Mars , Venus and Mercury , for example.
Explosion craters , on the other hand, are those depressions caused as a result of an explosive material . If someone detonates a bomb on an urban highway, for example, it is likely to cause pavement collapse, among other disruptions in the surrounding area.
The depression left after the impact of a meteorite on a planetary body whose surface is solid, such as a planet, a satellite, an asteroid or a dwarf planet, is known as an astrobleme or impact crater .
It is important to note that the dimensions of the meteorites that reach the stars are very varied, since they can range from small grains of dust to immense bodies measuring several tens of kilometers . Its kinetic energy is such that it can cause fragmentation in the soil typical of an explosion , given its violence. There have been cases of meteorites with considerable masses that caused, at the moment of impact, the release of lava, which solidified and gave the craters a flat base.
Crater derives from a Greek term that means "vessel", and this is because its shape is similar to that of a bowl, as well as that left by the explosion of a bomb or a projectile, something that has been proven in several experiments. . Impact craters never arrive alone, but cause a large number of changes in the landscape due to the great violence with which the meteorite impacts the earth; For example, breccia appear (detrital sedimentary rocks that are 50% formed by stone fragments fused by a natural cement).
Craters appear less frequently on planets that have a gaseous envelope, partly because friction with the layer of gas called the atmosphere sharply decreases the speed of meteorites. This friction also heats them considerably, reaching thousands of degrees Celsius, and this can lead to three phenomena , depending on the physical characteristics of the meteorite:
* It can volatilize very far from the planet and fall slowly in the form of meteorite dust;
* it can disintegrate near the surface because of the difference between its interior and exterior temperatures;
* It can wear out considerably during its journey (this is known as ablation ).