What is the bolide?
Bolide is a general term for any object from an area that collides or explodes in the atmosphere. It covers meteorites, asteroids and comets. In astronomy, this term is often used to describe a meteor, which is brighter than the size -4 -asi as clearly as the planet Venus -a uses synonymously with a "fiery ball". In geology, the bolide is generally used to describe a meteorite or asteroid that leaves a crater of impact, and tends to be used where there is not enough information for a more specific description. These objects have different compositions. Some can be described as "dirty snowballs" - dust and small fragments of the rock freely held together with ice - while some may consist of dense rocks with a high metal content, mostly iron and nickel. Surrounding at up to 26 miles per second (42 km/s), compared to 18 miles per second (29 km/s) for the ground.
depending on the direction from which they approach, they can enter the Earth's atmosphere up to 44 miles per second (71 km/s). In these rThe friction with the atmosphere quickly heats the object to very high temperatures, causing it to shine clearly. Very small objects will be completely burn in the atmosphere, but larger objects may, depending on the size and composition, hit the surface or explode in the lower atmosphere.
Most of the objects that enter the Earth's atmosphere are around the size of the grain of sand. They burn quickly, but are visible from the surface like meteors. Bolides, which reach the surface, can leave bumps. Numerous such craters can be seen on the Moon; On Earth, however, erosion and geological activity tend to erase evidence relatively quickly, geologically. There are only a few impacts of Cratna Earth that are sufficiently preserved to be obvious as such; The best example is Barringer Crater in Arizona, USA - roughly a circular crater of over 1,000 yards (1 km) wide.
a large collision of the bolide may have a devastating effect onthe planet. In addition to immediate effects on the area surrounding the impact, a large amount of evaporated rock would be powered into the upper atmosphere, where it would condense into fine dust. This could significantly reduce the amount of sunlight reaching the surface throughout the planet all the time, killing green plants and seriously lowering temperatures.
Perhaps the best -known example of the main event Bolide is the one that appeared at the end of the chalk of the geological period 65 million years ago. Evidence of a large crater with a diameter of 110 km (180 km), dating from this time, was found on the Yucatan Peninsula in Mexico near Chicxulub. It is assumed that the subject of average is about 6 miles (10 km).
This object is generally believed that it caused the event of a mass extinction that occurred at that time, and deleted dinosaurs and many other animal classes. But not all scientists agree that the impact of Chicxulub was solely responsible for this extinction event and some think maybe there have been a number of big impactsat. During the country's history, there were several events of mass extinction and some or all were caused by large bolides.
The largest bolide fiery ball, which is known to see people, was the event of Tunguska in 1908, when there was a huge explosion over the Tunguska area in Siberia, causing extensive devastation. Fortunately, the area was uninhabited and there were no known human sacrifices, but the shining path and detonation of the building witnessed a number of people in villages a few distances. Computer simulation based on the destruction formula calculations, access angle and possible composition of an object that is assumed to have been a small asteroid or comet fragment.