Studying asteroids that approach Earth
1908, there was a big explosion near the Tunguska River in Russia at the beginning of the day. There was no causality, but the witnesses reported a bright blue flash followed by thunder and a flash of glass. Almost 10 years later, scientists have led an expedition. They observed unusual features, such as trees that appeared to have been burned, standing and without branches.
The team was disappointed to have not found a crater or meteorites.
Since then, much research has focused on “impact” – it is important to be the only test case for the impact hypothesis.
Periodic reports that appeared in the days following impact were collected to establish side effects – an earthquake occurred on the Richter 5 scale. Shock waves were detected.
The devastated area was about eight kilometers wide. Atmospheric effects have also been reported. People saw about 100 km of a cylindrical pillar of light blue fire down near the horizon just before the earthquake shook buildings.
Impact is a concern for all of us. Such a study is important so that we can survive. Several hypotheses have been developed. Although it is stated that these are comets, another said that it was a sudden release of natural gas from the earth itself.
The possibilities of these studies are rare. A collision of an asteroid in Chelyabinsk February 15, 2013 provided another opportunity: the asteroid much less the size of a small plane and exploded without creating a crater. The effect of the impact was 500 kilotons in the air blast.
Eugene Shoemaker, an Americangeologist and one of the founders of the field of planetary science, who proposed the Impact theory of lunar craters has also made estimates of impact energy. The effects on the atmosphere, the biosphere have been well studied. It states that the impact was responsible for the massive extinction of dinosaurs 65 million years. The impact crater is identified by a huge circular area known as the KT boundary near Mexico.
The importance of studying these asteroids approaching Earth was made some time ago and special research projects have been initiated. Tracking near-Earth asteroids (NEAT), researching near-Earth asteroids of Lincoln (linear) and similar uses robotic telescopes to explore the sky so that the body moves quickly near the ground. Near-Earth asteroids may be too small to be seen even with moderately sized telescopes. A record of potentially dangerous asteroids near Earth (Phnea) is maintained and these objects are tracked.
The Phnea list increases rapidly with the arrival of new sensors and new tracking telescopes.
There are still a million identified asteroids that could be derived from this list. The approximation distance is usually given in LD units, which represents the lunar distance (384,000 km). For example, the designated asteroid 2014 BS5 moved to land at a distance of 3.12 LD July 23. This is approximately 30 to 50 m in diameter (if circular), and will be a good target for study using radar images.
Therefore, Phnea pose a risk to the Earth, and the consequences of an impact can be serious. We have the technological ability to detect.
The most recent ideas about surveillance and diversion of dangerous people away from the impact of the earth are experienced.
There are a handful of asteroids crash on earth was known. Some of them had names like Lost City, Pribram, Peekskill and Innisfree. They were very small and their impact has not done serious damage.
However, there is a larger body that is known as long as they are land once every three or five years. The nearest approach to Apophis, about 370 km is scheduled for 13 April 2029, when it is likely to be at a distance of 36 000 km.
June 30 is observed as an asteroid day and commemorates the anniversary of the impact of a Tunguska asteroid.