The Science behind jets of plasma occurring all over Sun’s chromosphere

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The Science behind jets of plasma occurring all over Sun’s chromosphere

  • Scientists have unraveled the science behind the jets of plasma - 4th state of matter consisting of electrically charged particles, occur everywhere in the sun’s chromosphere.

Plasma Jets

  • These jets or spicules appear as thin grass-like plasma structures that constantly shoot up from the surface and are then brought down by gravity.
  • The amount of energy and momentum that these spicules can carry is of fundamental interest in solar and plasma astrophysics.
  • Spicules come in all sizes and speeds.
  • The physics behind the short spicules is different from that of taller and faster spicules.

The Chromosphere

  • Just above the photosphere is the chromosphere.
  • It is relatively a thin layer of burning gases.
  • The chromosphere is a bit cooler - 4,320 ֯C.
  • The chromosphere is 500 times lighter than the plasma in the photosphere.

The Science of Plasma

  • The plasma right below the visible solar surface (photosphere) is perpetually in a state of convection, much like boiling water in a vessel heated at the bottom.
  • It is ultimately powered by the nuclear energy released in the hot-dense core.
  • The convection serves almost periodic but strong kicks to the plasma in the solar chromosphere(a shallow semi-transparent layer right above the visible solar disk).

The Study

  • To explore the underlying physics of spicule dynamics, the team turned to an audio speaker.
  • A bass speaker responds to excitation at low frequencies like the rumbling sounds heard in movies.
  • When a liquid is placed above such a speaker and the music is turned on, the free surface of the liquid becomes unstable beyond a particular frequency and starts vibrating.
  • A fluid like paint or shampoo will result in unbroken jets when excited on a speaker since its long polymer chains give it directionality.
  • The scientists realized that the physics underlying these paint jets must be analogous to the solar plasma jets.
  • The solar plasma can be imagined as threaded by magnetic field lines, much like the long chains in polymer solutions.
  • The study challenges this widespread belief to show that solar convection can by itself form all kinds of jets - short as well as tall.
  • The simulations were able to reproduce a forest of jets because they explored a more realistic range of parameters than earlier studies.


  • This novel coming together of solar astronomers and condensed matter experimentalists was able to reveal the underlying cause of the poorly understood solar spicules.
  • The power of unifying physics that connects physically disparate phenomena will prove to be the driving force of much more interdisciplinary collaboration.