Why in the News?

In a rare phenomenon, researchers from the Indian Institute of Astrophysics (IIA) have recorded the auroral activity that is normally witnessed over the North Pole- at Hanle and Merak in Ladakh through the all-sky cameras recently.

What is Stable Auroral Arc (SAR)?

• An aurora is a glorious curtain of light that is usually seen at high latitudes like in the Scandinavian countries, and they are not expected to occur at lower latitudes.
• They occur due to the interaction between the Earth’s magnetosphere and the incoming solar wind that carries charged particles and magnetic fields.
• They are typically several hundred kilometers wide and can extend for thousands of kilometers.
• A Stable Auroral Arc (SAR) is red in colour as opposed to the usual green-blue curtains of light seen from high latitudes.
• It is a rare phenomenon and it was not exactly an aurora-like one witnessed from close to the North Pole.
• SAR arcs are typically subvisual, meaning that they cannot be seen with the naked eye.
• However, they can be detected using specialized instruments, such as photometers and spectrographs.
• It was observed in Ladakh during a strong G3-class geomagnetic storm and this event was registered in many parts of the world.