Tuesday, February 16, 2010

The Great Total Solar Eclipse of 16 February 1980

Eclipses of the Sun and the Moon as viewed from any place on Earth are possible only because of a fortuitous and accidental circumstance associated with the Sun and the Moon. While the Sun is about four hundred times bigger than the Moon, it is also nearly as many times farther away from the Earth as is the Moon. Therefore they appear to be of nearly the same size (about 0.5 degree in angular diameter) as seen from the earth. On the occasions when these three bodies are nearly in a line, solar or lunar eclipses, which may be partial or total, are possible. A partial solar eclipse results when the lunar disk hides only a portion of the solar disk on a new Moon day. A total solar eclipse happens on the rare occasion when the lunar disk is slightly larger than the solar disk and blots it out of sight from the earth at the viewing site. This is an extremely rare event at any specific place on earth and lasts only a few minutes during which day turns into night and produces some breathtakingly beautiful effects.

The first total solar eclipse of the twentieth century visible anywhere within India occurred on 16 February 1980 (exactly 30 years ago to this day – Tuesday, 16 February 2010) and was visible late afternoon over many parts of south central and eastern India (see figure). There was an intense anticipation of the event among those seriously interested in astronomical phenomena. However, media interest was not as extensive as the nature and rarity of such an event deserved. Surprisingly, there was little or no interest evinced by students, teachers and the general intelligentsia which included the vast majority of ‘educated’ people. School science teachers who taught about eclipses using blackboards in their classrooms appeared to show no interest in observing a real one, especially one that promised such a great spectacle! At that time I was a research fellow in the Raman Research Institute in Bangalore and wanted to view the event from a good location with my family and some colleagues.

The famous Tungabhadra dam is situated on the outskirts of Hospet in Bellary district of Karnataka and the region is even more famous for the UNESCO designated world heritage site of Hampi which was the seat of the Vijayanagara Empire in a bygone era. We decided on this location with the twin objective of seeing the eclipse from the top of Vykunta hillock adjoining the dam as well as exploring the ruins of Hampi nearby. Preparations for the visit were begun weeks in advance and bookings made at a government guest house near the dam. I had studied available technical literature on eclipses extensively and was fully tuned to the expected sequence of events beginning around 3.40 PM and lasting less than three minutes of totality on Saturday, 16 Feb 1980. The partial phase that was to begin much earlier and last a few hours was not of much interest.

I had mounted my binoculars on a camera stand and improvised an attachment which would show a large back projected image of the Sun on a sheet of white paper. This was meant to view the event only during the partial phase. The moment totality began this had to be discarded and the human eye had to take over. I had fixed a solar filter to one of the objective lenses of the binoculars so that I could get a considerably enlarged view of the eclipse by looking through the corresponding eyepiece directly, especially during totality.

While eclipses are of great scientific and visual interest for some, the vast majority of people in the country look upon them as unwelcome and evil events which affect their personal lives negatively and from which they need to protect themselves! Many of them literally lock themselves up in their homes and come out only after the ‘evil’ has receded. Most shops, hotels, schools and offices are usually closed, streets are virtually deserted and life comes to a near standstill. It is only the insignificant minority of diehards immune to superstitions and blind beliefs who venture out and try to view such events. Even among them, many are unaware of the potential dangers of seeing the bright Sun directly with their naked eyes. Very few possess the right kind of solar filters for seeing the Sun safely. Some people who do know that it is unsafe to see the Sun with the naked eye assume that it is equally unsafe to see the total solar eclipse (when the Sun is in fact not visible at all!) with bare eyes and so keep off and miss out on a great opportunity. On that memorable day the vagaries of human behaviour I observed in Hospet was no different from what was seen in the rest of the eclipse belt in the country.

At our viewing site, as the totality phase approached, excitement grew among the measly crowd of fifty odd people who had gathered there to defy social norms and see the eclipse for what it really was. Minutes before the onset of totality (‘second contact’ as it is known by astronomers) there was a rapid dimming of ambient light and a noticeable cooling of the air around us. We were geared to look for several events in rapid succession moments before second contact – the fantastic diamond ring effect, Bailey’s beads looking like a necklace, the shadow bands that could be seen especially on a concrete floor, the day turning into night though not very dark, the sudden appearance of the wispy, glowing solar corona which is easily the most spectacular sight of the whole event, the appearance of bright stars in the darkened sky, visibility of planet Venus and even Mercury, the perturbed behaviour of birds due to the unexpectedly early sunset, and so on. We were fortunate to see each and every one of these phenomena in the expected sequence on a beautiful and totally cloudless sky. Alas, the eclipse was over before we had time to absorb the full impact of these breathtaking events. The final act before the end of totality (third contact) was another glorious diamond ring. Of course we had to turn our eyes away from the Sun immediately after this. The rest of our stay at the observation sight was spent in jumping up and down in sheer joy, recalling and narrating to each other the glorious sights we had witnessed and a casual view of the partial eclipse visible thereafter. 

In 1970 Dr Fred Espenak, perhaps the best known authority on eclipses and often referred to as “Mr Eclipse”, wrote: “I had read all I could about solar eclipses, but I was quite unprepared for the experience of totality. It was electrifying, sublime, awesome and humbling all at the same time. I managed to make a couple of photographs of the total eclipse, but they pale in comparison to the images of the event that were burned into my mind's eye. I knew that I just had to see another eclipse because it all happened way too fast.”

I have had the chance to travel widely both within and outside the country, seeing some of the great sights in the world. These include natural wonders like the Niagara Falls and Jog Falls as also the recent total solar eclipse of 22 July 2009 which I saw in China (This will be the subject of my next blog entry). Among the great man-made wonders I have seen are the Taj Mahal, the Great Wall of China, the Coliseum in Rome (which in my view doesn’t deserve to be treated as one of the Seven Wonders of the World) and the Forbidden City in Beijing (which is good enough, in my view, to replace the Coliseum in the wonders list). But none of these comes anywhere close to the fantastic spectacle of nature I saw on 16 February 1980 for just a little over two minutes. It is quite simply the grandest and most memorable event in my whole life. In some respects it was also a sad day since I was witnessing a total eclipse of reason among civilized human beings even as I was watching one of the grandest spectacles put up by nature. I am taking this opportunity to talk about it on the thirtieth anniversary of the event, but it is so permanently etched in my memory that I feel as if it happened just yesterday.

A Tailpiece: Dr S V Narasimhan of Virajpet, Coorg District, Karnataka has a fascinating description of the total solar eclipse of 1980 he observed from a location on the western coast. His experiences and observations parallel mine closely. However, I have disputed his claim that he observed the eclipse from the coastal town of Bhatkal as he narrates (in Kannada) in his blog*. This town falls outside the totality belt. Initially I thought this was a cartographic error, but the google map on which the information is based is known to have an uncertainty of only a few metres, not the 20-30 km needed to place Bhatkal inside the totality belt. He intends to resolve the issue by actually retracing his adventurous route that day and trying to identify the exact location from where he observed the event. I am eagerly looking forward to his findings.


Physics My Passion said...

Dear Prof Prasad
I enjoyed reading your first person narration of solar eclipse of 1980. It is interesting, readable and certainly inspiring for young minds of today. I look forward for your new blogs. Thanks. Mallesh

N.Ramkumar said...

Dr Prasad
I enjoyed reading your narration of solar eclipse.
will like to read more of your blogs
wipro fellow

Anonymous said...

Hello sir.
Please can I have the dates of solar eclipse in December 1980?
The article was excellent.

Anonymous said...

Hello sir..
I was born on 16th feb 1980.. when sun light was minimum..as all close relatives tell.. bhiwani( haryana).. dr manoj...(pediatrician).

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