Plasma in astrophysics and it's space occurance

"There are endless planes of attention, endless realities and endless mind states. They are like collections of atoms and protons and neutrons. They just go on forever. They are plasma..., they are fluid.....they are alive." - Frederick Lenz

What is PLASMA?

A hot ionised gas consisting of approximately equal numbers of positively charged ions and negatively charged electrons often we called it as fourth state of matter. Plasmas have no definite volume or shape but these are electrically conductive and magnetically active.

Plasmas have two properties quasi-neutrality and collective behaviour that differ it from other states of matter. Quasi-neutrality is the apparent charge balance of plasma and all particles of plasma behave in similar manner showing collective behaviour.

cosmolearning.org

Discovery

In 1879, Sir William Crookes discovered the existence of plasma in Crookes tube and called as radiant matter. In 1927, Irving Langmuir Coined the term “PLASMA” as it remind him as blood plasma.

"I have never thought that you could obtain the extremely clumpy, heterogeneous universe we have today, strongly affected by plasma processes from the smooth, homogeneous one of the Big Bang, dominated by gravitation."- Hannes Alfven

How plasma formed?

When more heat is provided to atoms or molecules, they get ionised. Electron gain enough energy to escape from the atoms and after escape of electrons, atoms become ions. In sufficiently heated gas, ionization happens many times creating clouds of free electrons and ions. The ionised gas mixture consisting of ions, electrons and neutral atoms is called the 4th state of matter i.e PLASMA.

If we further increase temperature and condensed then we can produce another higher state i.e the 5th state of matter called Bose-Einstein condensate(BECs).

Also read- Fifth state of matter: BEC- A recent revelation.

Different types of plasma

Plasma can be divided into different types like astrophysical, terrestrial and artificial plasma. Terrestrial plasma occur in lightening bolt, auroras, ionospheres and extremely hot flames. Similarly terrestrial plasmas are the man made plasmas like plasma TVs, plasma coating, plasma torch, fluorescent light etc.

Astrophysical plasma is the plasma that present outside the solar system include All stars, Solar winds, Interstellar nebulae, Interstellar medium(space between stars), Interplanetary medium (space between planets), Intergalactic medium (space between galaxy), Accretion discs etc.

Solar wind containing plasma (wdrfree.com)

Sun is an example of stars in plasma state.

Where is Plasma found?

Space is not an empty vacuum rather it is full of plasma which conduct waves of electricity. From the begining of universe i.e from Big Bang, the universe was in the state of plasma. Later reionisation of universe takes place. 

As plasma is a very hot ionised gas we can not mostly find it in nature or here on Earth. But the best example of naturally occuring plasma is lightning. The entire universe is formed from plasma about 99% of the matter in observable universe present in plasma state. In our solar system, the sun, interplanetary medium, magnetosphere & ionosphere of Earth, comet tails, certain planetary moons also consist of plasma. 

Plasma Applications

Plasmas have different important applications from the field of space science, medical diagnostics to rocket science field. Plasma used in space craft, all types electric propulsion. 

Plasma thrusters are one of the most important relevant application in the field of rocket technology. Plasma rockets have high thrust and high impulse and can capable of reaching over long period of acceleration. Electrothermal plasma thruster named VASIMR that uses radio waves forms plasma which used in spacecraft propulsion.

variable Specific Impulse Magnetoplasma Rocket
(en.wikipedia.org)

Besides all these plasmas also used in many other fields of industrial applications, new material synthesis, to drive laser and particle accelerator, different LCD fabrications and manufacturing different semiconductors etc.

Plasma is the object of study as plasma physics including sub-discipline as space plasma which includes many important applications in the area of space science to the field of medical diagnostics currently involves in the various field of active researches and challenges across many journals. Plasma is now considered as new area of research and development due to it's great features, wide range of applications, powerful energy source.