Just as we earthlings feel the flow of air along with witnessing its catastrophic nature, so does exist a kind of uninterrupted flow in space. Our sun is fully responsible for this flow. We know this flow in space as Solar Wind. This type of flow is not only confined to our solar system, it is also generated from any star and spreads rapidly around it. This is a very normal phenomenon. Today we will try to know something about this in a preliminary way.
The
corona is the heated region of the outermost layer of the sun. The sun contains
the fourth state of matter. This fourth state of matter is called plasma. At
very high temperatures, the bond or force of attraction between the particles
(protons, neutrons, and electrons) inside the atom of matter collapses. This
state is the plasma phase of matter. These charged particles are released from
the outer layer of the sun or corona which is called solar wind. The charge of
these particles is usually between 0.5 kV to 15 kV. These particles originate
from a variety of elements in stars. Observations of various stars have shown
that these elements are carbon, nitrogen, magnesium, silicon, sulphur, iron,
neon, etc. However, sometimes the presence of released ionized particles from
phosphorus, titanium, chromium, nickel is observed. The density, speed,
temperature of the solar wind depends on its source i.e. the star. All these
particles are hitting our earth with great speed but the strong magnetic field
of the earth is protecting us from all these harmful particles and creating an
impeccably beautiful aurora in the dark polar sky.
At first we had no idea that these particles could come from outside the earth. The subject was first enlightened in 1859 by the British scientist Richard Carrington. He and another English publisher and amateur astronomer, Richard Hodgson, later studied the particles separately and named it Solar Flare. The Irish scientist George Francis FitzGerald stated that the flow of such particles from the sun is a very common phenomenon and that these released particles reach the earth a few days later. Norwegian scientist Kristian Birkeland was the first to express that particles (positive and negative) in the solar wind are ionized. This is what the British scientist Frederick Lindemann said in 1919. In the 1950s, the German scientist Ludwig Biermann said that, the tail of a comet, orbiting the sun, is always on the opposite side of the sun because of the blow of this solar wind. The term 'solar wind', the ionized particle from the sun, was first used by the famous American scientist Eugene Parker.
This
information about the solar wind made people so interested that various
spacecraft collected information about this during their missions and sent it
to Earth. The first name that comes to mind when talking about this is the
former Soviet Russian spacecraft Luna-1. The spacecraft measured the energy of
the solar wind in January 1959 and based on that Luna-2, Luna-3 and Venera-1
spacecraft conducted further research. The same subject was studied by the US
spacecraft Mariner-2 in 1962 with the help of scientist Marcia Neugebauer and a
team of scientists. In 2006, NASA launched two spacecraft to study the sun.
These two spacecraft were named STESEO or Solar Terrestrial Relation
Observatory. The high-powered special cameras of these two spacecrafts have
taken pictures of the solar wind. The main purpose of these two spacecrafts is
to determine the mass of solar particles emanating from the corona of the sun
and to study the corona. In 2018, NASA launched the first spacecraft named
after a living person. Named the Parker Solar Probe, the spacecraft will orbit
the sun a total of 24 times in the 7 years of its operation and will conduct
detailed research on the nature of the corona and more. It will also study the
origin of solar winds, their high kinetic energy and temperature. As it orbits
the Sun, the nearest distance to the Sun will be 0.04 AU or 59,83,915 km. (AU
or Astronomical Unit: The average distance of the Earth from the Sun.
The actual value of it is 14,95,97,871 km) Also, after the Voyager
spacecrafts passed the Heliopause in 2012 and 2016 respectively, no more solar
particles were found. (Heliopause: According to space science theory
Heliopause is an imaginary boundary beyond which there can be no solar wind or
solar particles) That is, after the boundary of the solar system, where the
Sun's gravitational pull is no longer different from that of other stars, the
solar particle no longer exists at an estimated 50,000 AU or 2 light-years
away. This region is called the Interstellar Medium (Interstellar Medium:
The vast region between two or more stars in a galaxy where gases are
present either in ionized state or atomic state or stable condition along with
cosmic rays and dust)
(Here
is the link to know more about Voyager spacecraft https://spacejagat.blogspot.com/2020/02/voyeger.html )
At
first it was thought that the reason why solar particles are so fast may be
because of the very high temperature of the sun. But later, in the 1960's,
various experiments showed that it was never possible for solar particles to
have such a strong kinetic energy only due to very high temperature. This may
be influenced by some other unknown force. It is also thought that this high
motion may have some relation with Sun's magnetic field. However, it is not
possible to say anything clearly about this right now. The speed of these
particles near the corona region of the Sun can range from 145 km/s (5,22,000
km/h) to 400 km/sec (14,40,000 km/h). After covering the distance which is
equal to few radius of the Sun, the speed can range from 250 km/s (9,00,000
km/h) to 275 km/h (9,90,000 km/h). However, this speed is much lower than the
Sun's escape velocity (617 km/sec or 22,24,800 km/h). (Escape velocity: The
minimum velocity required to get rid of the gravity of a cosmic object.)
For a small size, the electrons acquire a velocity of release within this
velocity, which naturally generates an electric field. For this electric field
the velocity of the solar particle is further accelerated.
On
an average, 1.3 X 1036 particles come out of the sun every second
through the solar wind. Running at this speed, 0.01 percent of the sun's mass is
decayed every year. It would take the earth 150 million years or 15 crore years
to decay this amount of matter.
Solar
wind is generally of two types namely Slow Solar Wind and Fast Solar Wind. The
speed of Slow solar wind is usually 300 km/sec or 10,60,000 km/h near the point
of origin. Sometimes this speed can increase up to 500 km/sec or 18,00,000
km/h. The average temperature of this type of particle is usually 100 mega Kelvin.
Their place of origin is usually the equatorial region of the sun. However,
when the number of solar spot in the Sun increases, they originate from the
polar regions of the sun. On the other hand, the speed of a high-speed solar
particle near its place of origin can be up to 750 km/sec or 27,00,000 km/h,
and the temperature can rise to 800 mega Kelvin. These particles emerge from a
temporary funnel-shaped structure in the corona region, just 20,000 km above
the Sun's Photosphere. However, the density of slow-moving particles is higher
than that of high-speed particles in per cube unit area.
The
speed of both types of solar winds is interrupted by occasional solar plasma
explosions. This explosion of plasma is called Coronal Mass Ejection (CME).
This phenomenon is usually caused by the magnetic force of the sun which we commonly
refer to as Solar Storm. In mid-July 2021, such a powerful solar storm swept
across the earth. Sometimes solar winds can flow together with solar storms. If
the effect of a planet's magnetic field does not cause aurora in the
atmosphere, or if the comet's plasma tails do not cause these solar particles
to become motionless, then the motion of other cosmic particles in the Heliopause
region at the edge of the solar system slows them down. This phenomenon is
called Terminal Shock Wave (TSW). The boundary of the solar system that we have
defined for our own convenience is somewhat approximate. It is not yet possible
to know the exact limit of our solar system. Attempts are being made to
determine that boundary based on the motion of the solar particle and the
density of other particles in the Interstellar region. The IBE (Intercellular
Boundary Explorer) spacecraft has been launched in October 2008 to help
scientists in this regard.
Planets
and satellites that have strong magnetic fields can easily resist the solar
wind. Here solar wind is reflected by the Lorentz Force. (Lorentz Force:
The kinetic energy that is generated when an electric field and a magnetic
field exist at the same time in a particular place is called Lorentz Force.)
In planets and satellites where there is a weak magnetic field, the solar wind
removes the thin atmosphere of that planet or satellite forever.
When
the solar wind blows over the earth, its various effects can be seen inside and
outside the earth. These particles temporarily affect the Earth's magnetic
field, temporarily lose the ability to determine the direction of the compass,
create auroras in the polar region, and so on. All of this is called a
Geomagnetic Storm. Scientists have analyzed data from the Cluster spacecraft
sent by the European Space Agency and discovered that there are some waves in
the solar wind that could easily penetrate the Earth's magnetic field in a way
that was previously unthinkable. From this, scientists can understand that the
density of the earth's magnetic field is not always the same everywhere, that
is, its density is variable. Its shape depends on the solar wind. The shape of
the earth's magnetic field is determined based on the speed, density and
direction of flow of the solar wind. In May 1999, NASA's two spacecraft, the
ACE (Advanced Composition Explorer) and the Wind, measured that Earth's
magnetic field was increased by 5 to 6 times. In this way the earth can resist
most of the solar wind. A very small amount of it penetrates and moves to the
ionized part of the upper atmosphere of the Earth's polar region and heats the
ionized particles in the air so much that these ions becomes extremely dynamic
and produces light. This is called the Aurora.
Although
Venus has resisted a bit, that luck do not happen in the case of Mercury or
Mars. Mercury is the one that has suffered the most from solar wind. Mercury
has the right magnetic field in terms of size and volume, but in order to be
closest to the Sun, it has to deal with the densest part of the solar wind,
which has made its atmosphere non-existent and radiation has also taken place
here. However, under normal conditions for Mercury's internal magnetic field,
the solar wind cannot enter its magnetic area. Only during solar storms does
some particles come in contact with the surface of Mercury. Due to the
influence of the solar wind, Mars lost one third of its atmosphere and is now
able to hold only one hundredth of the Earth's air density. The ‘Mars Atmosphere
and Volatile Evolution’ or MAVEN spacecraft, launched by NASA in 2015, provided
scientists with information on the subject. Our nearest cosmic neighbor the
moon has no magnetic field so it has no atmosphere. The Apollo mission
confirmed that the moon was most affected by the solar wind.
Not
only does the solar wind have an effect on the planets and satellites, but the
solar wind also has a significant effect on this vast space. This solar wind is
largely responsible for forming the comet's tail and keeping it in the opposite
direction to the sun. We also have no idea how many known-unknown cosmic rays
are constantly falling into our solar system from distant space. Perhaps many
of these rays can be extremely harmful which is not yet in our knowledge. This
solar wind has severely affected all these cosmic rays, greatly reducing their
intensity and protecting all the solar system, including our earth. Every time
solar particles are emitted and its effect is falling on the sun. Studies have
shown that the continuous ejection of the solar wind causes the sun's
rotational speed to decrease slightly and the sun to lose its mass little by
little.
There is still much more research to be done on
this solar wind. Maybe there is some mysterious unknown source in this cosmic
subject. The secret history of many unknown facts of the cosmic creation will
be revealed to us little by little only if we know the information by
penetrating all those mysteries
DECLARATION: All The Images Have Been Sourced From Google.
