«Times” tells how not to wake the most powerful and the Perseid meteor shower this week when it is best to observe this beautiful phenomenon.
On This week the world’s inhabitants will be able to watch the spectacular night doomsday – Perseid meteor shower, the most famous and powerful of the meteor showers.
The first description of the flow is at 36 AD, it was noted that “more than 100 meteors flew in four directions.” Today, astronomers know that the appearance of the sky a large number of “falling stars”, flying from one part of the sky (radiant),
due to the annual passage of the earth through the tail of comet Swift – Tuttle.
This comet was discovered in the middle of the XIX century and returned to the Sun every 130 years.
By the way, it is the largest object that regularly passes relatively close to Earth – of 10 km. About the asteroid led to the extinction of the dinosaurs.
The name of the stream was because if the mind will continue to monitor its meteors ago, as a result they all converge at approximately the same point in the sky – not far from the star Gamma constellation Perseus.
Over the years of revolution around the Sun in an orbit the comet has left few traces of dust consisting of particles (meteoroids). As the Earth moves through the tail, meteoroids penetrate the atmosphere at a rate of tens of kilometers per second, heating, evaporating and causing a bright glow, which is called meteors.
In the case of the Perseids found that the particles collide with the Earth at a speed of 59 km / s,
so the largest of them, burning leave the sky track, which can be seen tens of seconds or even minutes.
The particles, leaving a trail in the sky, usually have a size of only a few millimeters, and only the largest can be measured in centimeters.
The periodic comet tails closer to Earth accompanied by an increased activity of the Perseids. The last time this happened in 2004 and 2009, in 2015 the activity of the Perseids are also expected to be above average.
On the Perseid activity each year is influenced by two factors. Firstly, it is closer to the Earth’s fresh comet trail, secondly, a favorable variance of cometary tracks toward Earth giant planets Jupiter and Saturn.
Meteor showers are strictly repeated a year later in the same numbers because the Earth’s orbit and have a fixed flow area of intersection with each other.
Our planet passes in this area not once, but over a number of days, as meteoroid swarm of particles has a rather big width.
The first Perseids began to appear in the sky in the middle of July, but increased the flow occurred in the first week of August. August 7, observers could see 10-15 meteors per hour. By the August 10 activity increased to 20-30 Perseids per hour,
and at the peak of its activity flow is projected can be up to 80-100 per hour.
This year, the observations of maximum meteor shower on the night of August 13 will be favorable for observations from the territory of Russia, when a comet trail of one of the four appeals will take place at a distance of 79 thousand. km away. This will take place on August 12 at 20.39 MSK. Waning moon phase 3% will be in the constellation of Cancer and will not interfere with observations.
After the high activity will fall twice every following night, so on the night of August 14 in the sky can be seen no more than 40-50 meteors per hour.
All of these estimates are valid for observation in the dark sky away from city illumination.
The end of the observations will have about 25 of August.
However, the activity of the Perseids is changing and for one night: with increasing radiant on the horizon growing frequency of meteors. So the hours before dawn, can give the most spectacular observation.
The enhanced activity of the Perseids should be expected from the observed annual traditional highs. However, visual observations in the European part of Russia, they are unfavorable to occur in the daytime. 
No comments:
Post a Comment