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November 14, the moon blocks part of the sun over Tonga

Nuku'alofa, Tonga

Wednesday 14 November will be a day to mark in your calendar as solar eclipse watch day. The moon will shift in front of the sun, blocking out part of its light. For Tonga it will be only a partial eclipse, not so interesting therefore, but still it will be a quite deep one, and what is more we shall not get anything else so good for a long time to come, so you better watch.

True, there will be another eclipse on 10 May 2013, but it will be much smaller than this one.

Then we shall have to wait until 3 July 2019 for the next one, which is not only smaller still, but also almost over when the sun finally rises that morning.

Equally poor is the eclipse of 20 April 2023, which will have barely started when the sun already sets that evening.

There will be small eclipses in 2024, 2025, 2028, which likewise happen close to sunrise and sunset.

Essentially it will not be until 10 March 2035 before a decent solar eclipse will occur in Tonga, visible in the middle of the day. And how many of us will be still alive then to witness it?

By the way, in the past we have not been treated by nature much better for a long time. The previous eclipse visible here on 12 July 2010 was at sunrise, and it was completely overcast that morning. 22 July 2009 gave an eclipse at sunset. I was in Kiribati that day, where it was total and beautifully visible, but Tonga only partial and hindered by the clouds. I cannot remember to have seen the eclipse of 7  February 2008, so I guess it was clouded out too. And so forth.

Anyway, everybody should be convinced by now that a solar eclipse in Tonga is quite rare, so we better may hope not to miss this one.

It all starts at 9:08 when the moon will make its first indent near the top limb of the sun. The moon will continue its path, reaching maximum at 10:20 when 54% of the solar disk shall be covered. And by 11:40 it will be over, the moon clearing the limb of the sun at the 4 o’clock position.

The usual precautions for watching the sun apply during a partial solar eclipse as well. Never look straight into the sun with the naked eye, or you may end up by becoming blind for the rest of your life. Always use a dark filter, a welder’s glass would be best. Simple sunglasses are not sufficient, unless your stack 5 or so together, but by that time the image of the sun would be so blurry, that you still cannot see anything. In former times we would recommend black/white fotonegatives, but they have become rare in this age of digital imagery. Also gone now are the VHS videotapes, which appeared to be good, dark filters. But although they largely blocked the visible light, they still let the invisible infrared light through, which still could harm your eyes.

The simplest and best method is just by projection. Take a sheet a cardboard and make a hole in the middle. The exact size of the hole is not important, anything between say 1 and 5 mm will be fine, but the results will be better if the hole is nicely round without fraying. A paper puncher hole may do. The smaller the hole the sharper the image, but the darker it will be. The bigger the hole, the lighter the image, but the less sharp it will be. Keep the sheet above a flat white surface (a floor or a wall, or another sheet of paper if needed) so that the shadow  of the former falls on the latter. One ray of sunlight will peep through the hole and will shine as a little solar image on the surface below.

Firitia Velt,

Fasi & Afi.