How are the colorful lights of auroras determined?
What is the reason that auroras can only be formed at the Polar Regions?
What is the effect of this wonderful sky phenomena over our lives?
One of the most magnificent sky phenomena, which Almighty ALLAH created, are "Polar Lights" which are natural light images we can see in the sky. Polar lights, or by their scientific name "Auroras", are one of the manifestations of Allah’s name "SANI" (artist). Polar lights are a night luminescence which could be seen in the Northern and Southern Polar regions. Auroras are one of the most visible effects of the sun towards the Earth. The auroras, which can be clearly seen at night have two names, the one seen in the Northern hemisphere is called "Aurora Borealis". The one seen in the Southern hemisphere is called "Aurora Australis". These lights can be seen mostly in September and April. Auroras fluctuate from east to west. When you look at them from the Earth, they appear in shapes of a bow and lines. It is only possible to see the full circle shape of the whole aurora from space.
How are auroras formed?
In the formation of this amazing natural light show, atoms which are very small and invisible to the naked eye also do not have any mind and consciousness, undertake a very important role. Auroras emerge as a result of the interaction of charged particles scattered from the sun with the Earth's magnetic field. The sun produces energy particles (ions) which radiate rapidly with a speed of approximately 300 to 1200 kilometers per second. The clouds are formed from the joining of these energy particles called plasma. The plasma stream, coming from the sun, is called solar wind. Some particles are trapped by the interaction of Earth's magnetic field and the solar winds emerging from the sun with a speed of approximately 1 million miles per hour after they enter the magnetosphere. These particles follow the magnetic lines of force leading down from the outer zones of the atmosphere to the ionosphere. When the electrons enter the upper layers of the atmosphere they face oxygen and nitrogen atoms, approximately 20 to 200 miles above the Earth's crust. In this way, atoms which earn electrons supported by high energy become loaded with an energy well above their capacity. Under normal conditions, when an atom or a molecule is loaded with this kind of high level of energy, they lose it by hitting other atoms rapidly. However, at altitudes between 80 and 150 km where molecular density is a few atoms per cubic centimeters, it is very unlikely for an atom to coincide with another atom to transfer its energy. Another way to lose this energy, which is formed as a result of this interaction, is through absorption of the light. In this way, atoms absorb the extra energy and spread this energy as light into the sky. The spreading of energy as light leads to the emergence of the colorful natural light shows seen in the sky.
How are the colorful lights of Auroras determined?
Auroras show quite similarity to the light coming from colored televisions. In the television, electron beams controlled by electric and magnetic fields in the image tube hits the screen and brighten it according to the type of phosphorus chemical matter which covers the screen. In the lights of an aurora, the color of the light which emerges will depend on the type of atoms and molecules colliding with the charged particles. Oxygen atoms, which can be found on high altitudes about 200 miles above the Earth, are quite rare and they form a completely red aurora. Oxygen atoms found on levels of altitude of 60 miles form a most common type of green and yellow color. Ionized atoms produce blue color and its shades. Neutral nitrogen molecules produce red and purple colors and their shades. Auroras meet their need of fuel to form light with the charged particles thrown from the sun. The more activity from the sun determines the more intense the auroras become.
What is the reason that Auroras can only be formed at the Polar Regions?
The formation of Auroras at the poles is connected directly to the earth’s magnetic field and the magnetic field lines which direct these lights. The world is like a magnet in the form of an ellipse and therefore has a magnetic field around it. Earths magnetic field is similar to the magnetic field formed by a rod-shaped magnet placed in the center of the Earth. The rods axis makes an angle of 11 degrees with the axis of Earth's rotation. This angle ensures that the geographic north and south poles are in different places than the magnetic north and south poles. Earth’s magnetic field is similar to the impact of a very big electric current. Magnetic field lines, which constantly change their places due to the movement of the Earths core, can be thought of as fine lines which get out from the South Polar Regions into the North Polar regions. Magnetic field lines that come from different angles and get into a single point weaken when they rise above the ground. This is due to their upside down cone like shape and because of this reason, a few miles above the Earth, the effect of the Earth's magnetic field decrease to zero and resets.
The particles in the solar winds can reach the Earth from the sections where the magnetic field is zero and Auroras can occur only in these places like the polar regions where the particles can reach the Earth. The Earth’s magnetic fields largest duty is to work as a shield which protects the Earth from the solar winds coming from the Sun. Almighty Allah informed us about this shield with a verse in the Qur’an as one of its miracles:
... We adorned the lowest heaven with lamps and guarded it. That is the decree of the Almighty, the All-Knowing. (Surah Fussilat, 12)
Auroras occurring in other planets
As a result of the observations made by the Hubble Space Telescope auroras are also detected on other planets. Two of the planets which auroras are detected on are Jupiter and Saturn. Their magnetic fields are much more powerful than the Earth's. The auroras observed on Jupiter are about a thousand times more powerful than the auroras observed on Earth. While the formation of auroras on the Earth is because of solar winds, the source of auroras on Jupiter are its satellites. Researchers observed that materials scattered from the satellite of Jupiter "Io", are imprisoned by Jupiter’s magnetic field. Researchers also observed auroras on Venus and Mars as well as on Jupiter and Saturn. Auroras on Venus, which does not have a magnetic field of its own, was observed in pieces with different varieties and bright colors.
Effects of Auroras on our lives
Scientists are thinking that auroras are not just a beautiful sky show. By researching them, they can help us to know more about solar winds, the effects of these winds on the atmosphere and how to benefit in a useful way from this high energy generated by the auroras. Despite their beautiful images, the benefits the auroras produce can also be a damaging phenomenon. In 1989, in the city of Quebec, a high electric current occurred on a night with intense Auroras. This current damaged a power station, broke communications and resulted in 9 million people without any electricity or communication for a long time. During auroras electric currents, they can reach up to 50.000 volts -20.000.000 amperes and as a result of this high energy in the atmosphere our current in our homes also begins to increase. When the current in our homes reach 120 volts and exceeds 15-30 amperes, the transmitter from the power station will cut off all of the electricity.
Auroras are another proof of our Almighty Allah’s Superior Power
All the events taking place in the universe, such as the movement of celestial bodies millions of light years away from us and the events occuring in the sun or rays entering the Earth’s atmosphere and several developments in the Earth’s layers are all under the control of Almighty ALLAH and occur with His will. Auroras are also created as a proof to help in our thinking that Allah has power over everything and encompasses all things with his infinite knowledge. Thinking deeply about this great truth is a responsibility for every human being who is a creature of Allah.
Allah stated this fact in a verse of the Qur’an like this:
"It is Allah who created the seven heavens and of the earth the same number, the Command descending down through all of them, so that you might know that Allah has power over all things and that Allah encompasses all things in His knowledge." (Surat at-Talaq, 12)