What is a solar wind?

Every moment, the Sun radiates into space a stream of ionized particles emitted by the outer layer (the solar corona) at a tremendous speed reaching 1200 km / s. Its endless "vortices" surround the Earth, permeate the space of the solar system, and even go far beyond its limits. All stars can emit it, and in this case it is called stellar wind. The flow of particles of the Sun can also be called the stellar wind of the Sun and there will be no error in this.

The history of the concept

The scientific idea of ​​a person about the world is constantly undergoing changes. The process of denying previous dogmas and concepts makes it possible to take a fresh look at existing reality.

For a long time, science considered the static crown of any star. That is, the force of gravity seemed to balance the pressure force of nuclear and thermonuclear explosions, and did not allow flows of red-hot matter to be released from itself into the surrounding space.

The English geophysicist and astronomer Sidney Chapman in his time created and developed the theory of the stability of the solar atmosphere. His hypothesis divided the astrophysical community. All this would continue to our time. However, a man was found who resolutely and irrevocably refuted the views of the famous scientist.

His name is Eugene Newman Parker. The American astrophysicist dealt a crushing blow to the concept of his English colleague. With his pioneering developments, he was able to prove the irreversibility of the outflow of matter from the crown. Moreover, a very curious fact emerged: as you move away from the Sun, the speed of the solar wind increases significantly, reaching supersonic values, then decreases and becomes stable. By the way, the boundaries of its distribution have not yet been determined and are waiting for their discoverers.

Measurements carried out on the first interplanetary spacecraft confirmed the conclusions of Yu. Parker. A little later, astronomers discovered similar stellar winds in the vastness of a number of galaxies.

How does the solar wind appear?

The reason for the appearance of a stream consisting of a mixture of positively and negatively charged particles is the plasma that constantly forms inside the Sun. It arises as a result of endlessly occurring fusion reactions, heating the center of the star to several tens of millions of degrees Celsius. The ionized gas heated in this way rapidly breaks out of the conditionally "limited volume", flying far beyond the boundaries of our star system.

Interesting fact: the limits of this volume are due to gigantic forces of gravity, "as if clogging the explosions of many hydrogen bombs of an unlimited volume", arising from the enormous size of our luminary. And it is 109 times larger than the Earth. The result of the process is the heating of the corona of the sun to a million degrees Celsius, due to a series of microexplosions of the plasma “bursting free”.

In September 2016, American scientists using NASA STEREO observatories for the first time managed to detect the process of the occurrence of the solar wind. According to their statement, what is happening is identical to the release of water: first the stream flows in one stream, then it breaks up into separate particles, which become smaller and smaller until a gaseous “cloud” forms.

Study of the phenomenon

Seven years before Yu. Parker, the West German astronomer Ludwig Birman, studying the structure of comet tails, suggested the existence of corpuscular radiation from the Sun, now called the solar wind. A stream of charged particles, breaking through coronal holes (areas on the surface of our star not covered by a magnetic field), rushes into open space.

The first measurement of the technical parameters of the solar wind was made at the Soviet interplanetary automatic station Luna-2 in 1959.

Three years later, the American satellite “Mariner-2” performed months of research on a unique space phenomenon. Further studies were continued by the international station SOHO and a number of national management programs - NASA, USA. Scientific activity on the study of the solar wind has expanded its horizons from the surface of the Sun to the very edge of the stellar system.

Solar wind speed

Of great scientific and practical interest is the measurement, as well as the study of the laws of motion of the flow of hydrogen plasma, which forms the basis of the solar wind.
Originally ionized particles of helium, hydrogen, iron, silicon, sulfur and a number of other chemical elements move at a speed of 300-450 km / s.

Interesting fact: during solar flares or coronal mass ejections, the speed of the flow increases, up to 1200 km / s! The solar wind turns into a "solar hurricane", causing a whole set of unique natural and physical phenomena.

In the future, the solar wind speed of the stream increases, reaching 400 - 800 km / s near the Earth (this is where its acceleration ends). 1,500,000 km / h (420 km / s) in the Mars region. At a distance of up to 10 billion km from the radiation source, the speed of movement of solar charged particles is approximately - 1,000,000 km / h (280 km / s). Further, under the influence of the interstellar medium, it weakens.

The dynamics of the solar wind is influenced by two factors: the attractive forces of the sun and the pressure inside the stream. The calculations, backed up by practical research (flights of the American Voyager - 1, - 2 "and" Pioneer - 10, - 11 ") showed the constancy of the velocity of the outflow of oppositely charged particles already outside the orbit of our planet.

Types of Solar Wind

The nature of the ionized flow of the sun is ordered and is divided into two types:

• calm (slow or fast);
• outraged.

Calm - Slow

Slow solar wind occurs in the bowels of the equator of our luminary, during periods of thermal expansion of ionized gases. The dynamic process accelerates the coronal plasma to supersonic speeds of approximately 400 km / s. In its structure, the slow flow is denser and wider than the fast.

Calm - Fast

Coronal holes are the birthplace of the fast solar wind. The flows of this wind can expire for months, “attacking” the Earth with a periodicity of rotation of the Sun lasting 27 days.

Outraged

The cause of the perturbed flows is: the manifestation of the coronal ejection itself, as well as the appearance of compression sites in the interplanetary space before the upcoming coronal mass ejections or fast solar wind.

Interplanetary shock wave

The appearance of a cosmic shock wave is preceded by: “Attack” of a fast solar wind on a “slow brother”, Collision of a charged stream of coronal particles with the Earth’s magnetosphere, explosion of a supernova, collision of galaxies.

Interesting fact: a month and a half ago, a message appeared that NASA was able to measure the strength of the shock wave of the solar wind. Sequentially placing in space 4 specially equipped, equipped with the necessary equipment, multiscale satellites; American researchers literally “caught” a moment of scientific success. And double: as a result of the experiment, data of the highest accuracy on the nature and parameters of the motion of solar particles were obtained.

A shock wave is a collision region of a rapidly moving medium (gas) with some kind of obstacle (for example: the solar wind with the Earth’s magnetosphere), generating a “front” of a sharp change in the physical parameters of the incoming flow (pressure, density, temperature, particle charge level and a number of other indicators).

Solar wind propagation in space

Moving farther away from its "progenitor" - the Sun, the wind weakens and passes through several border areas. The first of them is removed from the luminary at a distance of 95 AU (AU - an astronomical unit equal to the average distance from the Earth to the Sun and amounting to 149 598 100 ± 750 km).The so-called “shock wave boundary”. It is on her braking of the solar wind from supersonic speeds.

Having flown another 40 AU, the flow of ionized particles under the influence of interstellar matter is completely inhibited. The boundary of inhibition determined by astrophysical processes is called heliopause. The spatial region bounded by heliopause is called the heliosphere. Its dimensions are not the same:

• 73 a.u. from the south side;
• 85 a.u. from the north side.

Astrophysical data were obtained due to the launch of 2 American spacecraft of the Voyager series, designed to study the boundaries of the solar system. More recently, Voyager 2 confirmed Voyager 1 data.

Solar wind and earth

Constantly changing streams of the solar wind could easily destroy all life on the surface of the Earth. To protect against such a "formidable weapon" there is a "reliable shield" in the form of a magnetosphere. The parity of this confrontation is quite variable and often causes geomagnetic storms. Not surprisingly, in 1990, the term “space weather”, which mainly reflects the current state of the Earth’s magnetic field, became relevant.

The creator of the science of heliobiology, studying the effect of our luminary on the vital functions of terrestrial organisms, was the Soviet scientist A. L. Chizhevsky. Thanks to him and a number of other researchers, it was possible to elucidate the laws governing the effects of differences in solar activity on the human body, increase and decrease the yield of cultivated plants, and multiply and reduce the populations of birds, fish, and animals.

The cyclicity of the periods of the impact of the Sun on the Earth was discovered and studied. Regular reports of the level of activity of the geomagnetic background have become commonplace. People suffering from chronic diseases have the necessary information to take the right medication in a timely manner. Modern crop and livestock production is also “armed” with knowledge in order to conduct its activities in the most optimal way.
Interesting fact: According to the observations of N. S. Shcherbinsky, the frequency of locust arrival in the fields coincides with the 11-year rhythm of the Sun.

Science goes ahead and calls for the young. Today, each of them can receive the specialty of a heliobiologist, having graduated from a specialized higher educational institution.

Natural phenomena caused by the solar wind

The solar wind, flying around the Earth, causes a lot of natural phenomena. Among them: magnetic storms, auroras, radiation belts of the planet. Not so long ago, a pattern was revealed in the increase in the number of lightnings from an increase in the flow of ionized particles of our star.

There are a number of geophysical phenomena generated by the solar wind. In some places, the output of gaseous radon from the earth's surface will increase, which can lead to an increase in radioactivity in the atmosphere. There is a correlation between solar activity and an increase in the number of earthquakes. A magnetic storm significantly changes the electric field on the Earth's surface and leads to jumps in atmospheric pressure.

Solar wind hazard

Powerful emissions from the surface of the luminary disrupt radio communications, interfere with the operation of computers, cause malfunctions in utility networks, and generate “harmful” electric currents in metal structures and devices.

The threats of solar wind attacks, leading to many problems, created the need for careful observation and prediction of magnetic storms on our planet. Weather services around the world are equipped with the necessary equipment, and constantly signal the fluctuations of the Earth's magnetic background. A technology has been developed to identify future foci of seismic activity and to warn the population of imminent danger.

Interesting fact: There is a scientific hypothesis of the occurrence of water on the lunar surface due to the influence of the solar wind.Detection of the liquid gives rise to hope and optimism in the prospects for the future development of the nearest space "neighbor".

Prospects for Using the Solar Wind

In the light of all the existing features of such a unique cosmic phenomenon as the solar wind, it becomes very interesting to find practical applications for it.
The pioneer in creating the so-called "electric sail", the "solar sail" (a spacecraft moving due to the energy of charged particles of the solar wind) was the Finnish scientist - Pekka Janhunen.

In the spring of 2013, the Estonian satellite ESTCube-1 equipped with this device was launched into orbit. Unfortunately, the attempt was unsuccessful, as the sail could not open.

There are other tempting projects: the use of streams of coronal matter to transmit information, or the creation of “ionostations” in the orbits of the planets to generate electrical energy.

The future of our sun

Scientific analysis gives a forecast for 5 billion years of the existence of our luminary. Losing every second up to 600 million tons of hydrogen, it is doomed to become first a red giant, and then a white dwarf. Along the way, having exhausted all its energy reserves in the form of hydrogen and helium. The most unpleasant thing is that the constantly expanding Sun will melt Mercury, Venus, and possibly the Earth. In any case, life on the planet will completely disappear.

So, humanity is obliged to think about its future and organize the resettlement to other worlds outside our solar system. It's unavoidable. Great minds: Russian scientist Tsiolkovsky, British astrophysicist Stephen Hawking, spoke directly about this. Moon, Mars, Ceres, Pluto - the list of potential colonies is expanding. So: "Let the solar wind blow into the sails of the spaceships of earthlings, storming the vastness of the universe!"