Were these Northern Lights over Ladakh?

People in Ladakh were in for surprise a few days back. The skies were suddenly set ablaze with brilliant, colourful lights. Scientists said that a strong geomagnetic storm struck the Earth’s magnetic field creating brilliant auroras. But auroras are usually witnessed at higher altitudes in parts of Norway, Alaska, and other countries. This was reportedly the first time that aurora was captured on camera in India. Social media was flooded with breath-taking pictures of this spectacular phenomenon. Amit Bhattacharya, Senior Editor with The Times of India, explains what happened in Ladakh.What are Northern Lights? How are these formed?Northern Lights are shimmering halos of light in the sky. They happen in different colours and are like curtains moving softly in the sky. In Northern Hemisphere it is known as Aurora Borealis and in the Southern Hemisphere it is known as Aurora Australis. The phenomenon is the same. These are formed due to charged particles coming from the Sun during events that are known as Coronal Mass Ejections. These strike the magnetic field of the Earth and move towards the Poles. They transfer their energy to oxygen and nitrogen in the Earth's atmosphere. Because of this, oxygen and nitrogen get charged and release photons of light. The images circulating in social media from Ladakh are not true. Scientists at the Indian Astronomical Observatory at Hanle, Ladakh, recorded the event on April 23-24. It is the second highest observatory in the world. Scientists here said the event was not Northern Lights as we know it. The images are of Stable Auroral Red Arcs, which are linked to auroral event. It’s a stable arc in the sky and does not move. On April 23-24, a strong magnetic storm was seen because of solar activity. At the scale of 1 to 5, it was a class 4 event, which means the storm was very strong that day. Northern Lights were seen across the world — in China, the US, California, close to the US-Mexican border, New Zealand and Australia. It was probably the biggest geomagnetic storm to hit the Earth since 2003. It's not impossible for Ladakh to have witnessed such an event, but perhaps it was much subdued than what was reported. Why are Northern Lights visible only close to the poles?The Earth has its own magnetic field which protects us from charged particles such as those coming from the Sun. When solar winds bring charged particles towards the Earth, they cannot get inside and move along the magnetic lines. At whatever position the charged particles hit, they move towards the poles because the magnetic lines originate from the poles. They can move either towards the South Pole or the North Pole. Have solar flare activities increasing?Yes. The activity of the Sun moves in an 11-year cycle. Cycle Number 25 began in the late 2019. In the middle of the cycle comes Solar Maximum, which is the point in time when solar activity is at its peak. This is expected to happen in a year or two. We are moving towards Solar Maximum, which is why we are seeing increased activity of the Sun and solar flares, Coronal Mass Ejections etc. What are the historical instances of enormous geomagnetic storms triggered by solar activity?The most well-known event is known as the Carrington event. It happened in 1859. It has been recorded as the strongest geomagnetic storm ever to hit the Earth. It resulted in Northern Lights appearing in many parts of the world. In fact, Northern Lights were seen even in Bombay. The Times of India reported that the Aurora was visible in 1859 over Bombay. I quote from the report: “After sunset on Sunday, the Aurora was slightly visible and constantly kept changing colour, becoming deeply violet when it was intense at about 3 o'clock on Monday morning. It was distinctly visible until sunrise on Monday. The influence of this atmospheric disturbance was unpleasant, both for our person and our correspondent. The cold was pleasant, unpleasantly keen, and all telegraphic communication was stopped for some hours.” From the US we had apocryphal reports of miners in California waking up much before morning. The light outside was so intense that they thought that morning had broken. They started preparing breakfast to prepare themselves for the day! It also shows that theoretically it is possible for Ladakh and other places in India to see Northern Lights. But these would be very rare events. Can geomagnetic storms disrupt electronic gadgets?Yes. Recently there were reports about a satellite going defunct because of geothermal activity. This is because what hit the Earth are charged particles. During the 1859 Carrington event, there were reports of telegraph lines getting burned because of strong magnetic field. The Times of India report that I talked about says the British Indian submarine cable, which was a telegraph line, suffered disturbances. It says the extent of this disturbance may be gathered from the fact that all the lines to England in connection with the British Indian submarine cable were affected for hours. Today, we live in a world where we are much more vulnerable to geothermal storms. We have become very dependent on satellites and the network they have generated. A sufficiently strong geothermal storm can have a big impact on the Earth. The photograph is a representational image.Audio Production: Prateek Kapoor