Tuesday, March 17, 2015

Northern Lights on tour in Moscow – BBC

On Tuesday evening, residents of Moscow and other regions of Central Russia were able to see the Northern Lights. Department of Science “Gazety.Ru” tells the story of what caused this colorful event, and warns that, perhaps in the next few hours it again.

On Tuesday evening, residents of several regions of Russia began to report that they were able to see the Northern Lights. And it was not only the northern regions – St. Petersburg, Novgorod, Karelia and Komi, but also the more southern areas, such as Moscow, Tver and Smolensk regions. With images of the aurora can be found from the photo essay “Gazety.Ru”, and this text will be told about the causes of this phenomenon and the probability to see him in the next few days.



What is the aurora?

Polar (northern) light – the glow of the phenomenon of the upper atmosphere of the Earth, caused by the movement of charged particles in the solar wind magnetic field of the planet. Usually auroras observed in the so-called auroral zones – areas-zones, which are located in high latitudes, as surround Earth’s magnetic poles. But this evening planet reached so powerful flash that the aurora was able to see the inhabitants of the more southerly latitudes, including in Moscow.

In order to understand the nature of the aurora borealis, imagine the Earth as a big magnet.

The poles of the magnet – the point from whence come the magnetic field lines of the Earth – are located near the geographic poles of the planet, but not exactly in them. Thus, the magnetic north pole of the Earth is located within the boundaries of the current Canadian Arctic, and, strictly speaking, it is the south pole, because attracts the north compass needle.

The charged particles of the solar wind are quite powerful energy, which is enough to produce ionization and excitation of atoms and molecules of gases that make up the atmosphere.

These excited atoms emit energy in the form of light, which causes the northern lights.

An analogue of this phenomenon – an experience which demonstrates discharge which arises when passing through the gas, an electric current. This happens when there is lightning thunder, but there we are talking about other energy values ​​than for auroras.

Scientists have learned quite well auroras and found that vozbuzhnennye oxygen atoms cause glow red and green colors. Violet and invisible infrared radiation cause eye ionized nitrogen molecule. The source of the faint red glow can be hydrogen atoms.



How to track aurora

In order to increase the probability of observing the northern lights, ideally, of course, need to be in the auroral zone. Surprise, similar to what was on Tuesday, at the latitude of Moscow happens every year, according to its current capacity of the northern lights experienced observers compared with what they saw in the 1980-90s. But in the north can not always expect a guaranteed good weather. For example, these days in Murmansk – and this is the area of ​​the Arctic Circle and guaranteed auroral zone – is a special group to observe the aurora borealis, which combined his trip there with the observations of the upcoming March 20 solar eclipse.

And you can imagine the frustration members of the expedition, due to the fact that on Tuesday in Murmansk was cloudy, and, for example, in Moscow, it was clear, that is very comfortable for auroral observations.

To the northern lights do not come as a surprise, Department of Science “Gazety.Ru” can advise monitor solar activity on specialized sites. Emission of charged particles the sun does not happen with the speed of light, such as solar radiation, and runs two or three days before the solar wind reaches the Earth’s magnetic field and causes in its atmosphere colorful flashes. In addition, not every solar flare will cause the aurora. Therefore, the easiest way – to follow the so-called average deviation index planetary magnetic field of the Earth from the norm – Kp-index. This logarithmic index, which is measured from 0 to 9 points. 5-6 points – a geomagnetic storm, 7-8 points – geomagnetic storm. In Murmansk, you can see the aurora at the value of Kp about 3, in Moscow – about 6.

Experienced observers of auroras in recent years began to establish itself on smartphones are special programs that inform that if Kp index begins to rise.

At the time of delivery of the material index, according to the site http://www.swpc.noaa.gov , which publishes information on space weather according to the National Oceanic and Atmospheric Administration (NOAA), Kp-index was 8. Animation auroras over the last hours can be seen that the area with auroras already gone to the north-west of Moscow.

But nothing prevents this area back: Current aurora was caused by a powerful solar flare was observed on March 15.

This Flash is not the only one: over the next 36 hours there were three outbreaks , and only Tuesday Sun calmed down a bit. So the science department “Gazety.Ru” advises often look at the sky at night as this, and the upcoming night.

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