11 July in Eclipses and Solar Physics

July 11, 1732 

French astronomer Joseph Jerome le Francois de Lalande (1732-1807) born. Calculated the distance to the sun in 1771 and being 154,198 million km.

July 11, 1909 

Simon Newcomb (1835-1909), American mathematician and astronomer died. He used carefully analyzed measurements of stellar and planetary positions to compute motions of the sun, moon, planets, and their satellites. Studied the velocity of light and calculated the distance to the sun. March 12, 1835 Birth of Simon Newcomb (1835-1909) in Wallace, Nova Scotia, Canada. Simon Newcomb died 11 July 1909 in Washington DC. 

July 11, 1991 

The so called Great Eclipse which was visible in Mexico and Hawaii. I observed the Total Solar Eclipse of 11 July 1991 in San Blas, Mexico. Until only one and a half day before "the" big day, it had been raining cats and dogs for more than two weeks. Water was literally and figuratively speaking in my shoes. But I didn't panic ... I had already "seen" about six eclipses. The morning of the total solar eclipse was magnificent. In spite of the party of the evening (read night) before, I got up at about 6 o'clock and sat down on a bench on the square. Observing the frantic, nervous "tourists" I was having a good time. The sky was bright blue and only at the horizon some strings of clouds seemed to drift. That was promising ! San Blas was constantly being beset by cars and buses packed with curious amateurs and tourists. It seemed a real invasion. Most of them went to the beach, some climbed up to an old ruin on the hill which offered a beautiful view. I still had to make up my mind. I had already been in this place for a couple of days and had been exploring the area. My wish list was not that long. About half an hour before the first contact I moved on and went observing the solar eclipse on my own at a remote spot, which was right outside San Blas, north of the little port at the coast. The view there was unique and splendid. I saw a vast plain with the ocean to the west and the beginning of the so-called "jungle" in the east. There were also some "barracks" of local Mexicans, sheltered under the branches of the trees. The little port was far away to the north and San Blas, the little village, was in the south. So there was enough horizon, and a little side shelter where I could hide from the heat. Some wild horses were roaming in the area, and in the sky I spotted a flock of pelicans. In the adjacent river some fish jumped up eagerly. This spectacle couldn't ruin the fun of my solar eclipse anymore. It was a divine, perfect place, far away from all the fuss and noise. The eclipse had already begun and as the moon was passing in front of the sun, it grew remarkably darker. Now and then I had to chase a mosquito or ... simply crush it with my eclipse cap. The ants on the ground received the same treatment. Some 10 minutes before totality, the pelicans began to fly at very low altitude. Well, fly ... I would rather call it gliding. Very peacefully and timidly. It had grown noticeably darker and the effect, as if you put on heavy sunglasses, had begun. It was a real sultry atmosphere. Shit ! I already began sweating from the emotions, enjoying this spectacle... The local inhabitants far away began to shout : "Don't watch, don't watch !!!" Anyway, they had been warned long beforehand by radio, newspaper or television not to look at the solar eclipse. Cases of blindness or eye injuries are typical in those countries. Meanwhile the fish stayed put under water. No mosquito was around anymore, believe it or not ! But the horses kept on grazing, as if nothing had happened. A few minutes to go ... and "it" would happen. The inhabitants (there were only four of them but they made enough noise for 20) became frantic, because it was so dark. Through the filter that I had taken with me, I could only see a small solar crescent, which was beautiful. I turned my head in every direction as if I were a chicken. I would and had to hear and see everything. The pelicans were gone. No, they weren't ! On the river, three of them were bobbing up and down on the water. The horses, without regard for what was happening around them, still were not satiated eating the grass. Totality ! Magnificent ! I nearly wet my pants. I was in a sweat. With the 10x50 I could easily watch the sun with the corona and the big solar prominence. A moment earlier, I had a beautiful view of the Baily Beads, but the diamond ring was not very spectacular. A big eruption was visible; it was simply perfect. Thanks to the long totality I was able to enjoy this natural phenomenon for a longer time than usual. I was lying in the grass (you should try it standing), using binoculars and now and then sitting upright to watch the surroundings. The horses ... I don't have to tell you anymore, I guess ... continued peacefully. But apart from them, almost no animal could be seen. Only the pelicans kept bobbing up and down on the water and the people were completely crazed, were shouting... In spite of the long totality (in San Blas it lasted 6m 23s) it wasn't completely dark. The horizon was still rather bright and beautifully coloured. Here and there one could see a light that people had lit. Stars or planets were not visible, because some clouds on those very spots obstructed them. I didn't worry, however, there was enough to look at. The moon moved on eagerly, and all of a sudden sunlight reappeared. People shouted with joy and applauded. Hundreds, no billions of mosquitoes attacked me as if they accused me of being responsible for this short night. In no time I looked like a leper. The horses didn't even bother to look up. It was over. A unique event as you can say. The partial phase had only just begun when a big cloud obstructed the sun. 

July 11, 2010 Jo and I observed the Total Solar Eclipse of 11 July 2010 in Mangaia, Cook Islands. Unfortunately, this had to be our second clouded out total solar eclipse (after July 22, 1990 in Finland).