Saturday, January 14, 2012

A rendezvous with Aurora Borealis

When I was a child I always used to be fascinated with the phenomenon called Aurora, that magnificent light show that nature performs in the latitudes closer to the north and south poles. So when I got a chance to visit Alberta in Canada in 2008, I knew it will be once in a lifetime chance to witness this which we are not privileged to watch in the tropics. But odds were heavily stacked against me to watch this because: 1) It is a rare and unpredictable phenomenon, though more regular during winters, 2) It should be a cloudless, moonless night, 3) we should reach the country side, which is an easy 100KM drive away from the city lights to watch this and hence 4) it should happen on that particular night that we rent a car. But I was optimistic.

Many of our local colleagues in Edmonton discouraged us saying it is a gamble and you have to be extremely lucky to sight it. But having crossed the seven seas to reach Canada, me and two other enthusiastic colleagues, Deepak and Saif, were ready to take the gamble. So we hired a car, drove off into the Alberta prairies on a shivering November Saturday night at 9:30pm. After driving for about 30 minutes, just as we hit Trans Canada Highway 16 away from the city lights, we could see the distinct greenish glow on the horizon that is so typical of the impending display of aurora. Initially we thought it is an illusion as we were so desperate to watch it, but as the glow became stronger we knew that nature was setting the stage for a grand performance. We immediately got off the highway onto to a country road heading north. Great thing about the prairies is that it gives great unhindered view of the skies all the way to the low horizon. So the spots for sky watching are yours for picking.

Pic 1: The distinct greenish glow that appears in the low horizon, a sign of an impending aurora.

After about 15 minutes drive, just as we reached a place far away from all city lights the show began. The auroras appeared about 40 degrees azimuth. We stopped the car, hurriedly setup the tripod and camera at -8 degree Celcius with only light coming from the Camera LCD. Yes, we were ill-equipped to work in the dark that night. Since I did not have a remote shutter release, I had to keep the shutter release pressed for 2 minutes in the freezing cold to get these pictures. It is not easy as after few seconds your fingers will start becoming numb due to the cold and it becomes extremely difficult to keep it pressed.  Later I realized that in the excitement of watching the aurora, I had set my camera at ISO 100. Damn, probably with a higher ISO setting of 800 or 1600 I could have got a sharper image, though grainy.

Pic 2 and 3: Auroras at the peak with Ursa Major overseeing the proceedings.

120 seconds exposure at ISO100, f/3.5 on a Canon 450D 18-55mm Kit Lens.

The show went on for nearly 30 minutes before the aurorae slowly vanished. But we were not satisfied. Got back into the car and waited till midnight, but the aurorae never returned. Looking back at that night, I feel nature was too generous for us. It was as though it was a special show arranged just for these three amigos from the tropic!

What is an Aurora?

An aurora is a natural light display high in the Earth’s atmosphere, caused by energetic particles from the Sun, colliding with the Earth’s magnetic field. This glorious show is called the Aurora Borealis in the Northern hemisphere and Aurora Australis in the Southern hemisphere, but are commonly known as the Northern and Southern lights.

Viewing aurora is incredibly simple, but the conditions need to be right for a display to appear.

Normally you can only see aurora near the poles, such as in Canada, Iceland, and Norway or southern Australia and Antarctica, but when the Sun is highly active, more solar material is thrown in Earth’s direction, creating powerful geomagnetic storms. These storms can bring auroral displays further south to areas such as Southern UK and North to mid latitudes of the USA. The intensity scale is known as the Planetary KP index and basically the higher the KP number the further south Aurorae can be seen, KP 8 or higher can be good for observers further south. To find out what current levels are check or the Geophysical Institute at the University of Alaska Fairbanks

The best time to spot aurora is around midnight, but this can change depending on viewing conditions and the current intensity of the magnetic storm. Once you are comfortable and your eyes have adjusted to the dark, face north (or south in the Southern Hemisphere). Look low and close to the horizon and look for the faint green/ reddish glow of aurora. It may be quite difficult to see at first, but if it is a powerful display it can be very easy to spot.

There is an aurora alert that has gone out recently due to a high solar activity and a large Sun Spot visible to the naked eye. Those who are in the higher latitudes, this is a great opportunity to watch this grand spectacle.

Pic 4: The real-time view of the range and intensity of the auroras provided by

Pic 5: Aurora intensity scale


Thank you Andrew Fazekas, a Canadian astronomer, for providing me the timely guidance through email to watch this (his website which has lot of useful real-time details: Also check out his video that graphically explains how auroras form: Details on “What is an Aurora” are borrowed from More details at