Solar Jets

• 09 Mar 2022

Why in News?

Recently, Scientists at Indian Institute of Astrophysics (IIA) have unravelled the science behind the jets of plasma on the Sun’s chromosphere.

• The Sun's chromosphere is the atmospheric layer just above the Sun's visible surface.
• IIA is an autonomous institute of the Department of Science and Technology, Government of India.

What are Solar Jets or Spicules?

• Solar plasma jets, or spicules, are powerful plasma streams constantly ejecting from the Sun’s chromosphere (an atmospheric layer above the Sun’s visible surface).
  
  • Solar jets, or spicules, appear as thin grass-like plasma structures that constantly shoot up from the surface and are then brought down by gravity.
• These jets rise and fall back under the influence of the Sun’s gravity, which is 20 to 30 times greater than Earth.
• Some jets are so energetic that they propel into the solar corona and beyond.
  
• The amount of energy and momentum that these spicules can carry is of fundamental interest in solar and plasma astrophysics.
• The four key ingredients favouring solar jets are the plasma’s fluid nature, gravity, strong quasi periodic triggers to eject the plasma and most importantly, the Sun’s powerful magnetic field giving it specific direction for ejection.
• The processes by which plasma is supplied to the solar wind, and the solar atmosphere is heated to a million degrees Celsius, still remain a puzzle.

Structure of Sun

What is the finding?

• The scientists observed how paint placed over bass audio speakers ejected as a forest of jets when a certain sound frequency and amplitude (speaker’s loudness) were surpassed.
  • When a paint is placed above a speaker and the music is turned on, the free surface of the liquid becomes unstable beyond a particular frequency and starts vibrating.
• The solar plasma can be imagined as threaded by magnetic field lines, much like the long chains in polymer solutions.
• They found that the underlying physics of paint jets when excited on a speaker is analogous to the solar plasma jets.
• The scientists elaborated that 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.
  
  • This is ultimately powered by the nuclear energy released in the hot-dense core.

What is Plasma?

• Plasma is a hot, charged gas made of positive ions and free-moving electrons that has unique properties distinct from solids, liquids and gases.
• At high temperatures, electrons are ripped from atom’s nuclei and become a plasma or an ionised state of matter.
• Plasma is also known as the fourth state of matter.

Source: PIB