On March 20 at 10.25am, many people paused their daily routines and looked up at the sun to witness a rare celestial event – the sun being partially eclipsed by the moon.
Contrary to what happens when there is a total eclipse, Malta was not shrouded in darkness. What we saw was the moon’s shadow covering 49 per cent of the sun’s diameter. It took the moon two hours and 15 minutes to move across the sun’s surface, with the first ‘contact’ happening at 9.21am and last ‘contact’ at 11.33am. Obviously there was no actual contact as the sun and the moon are 150 million kilometres away from each other.
It is only cosmic coincidence that allows us to see an eclipse. This is because the sun is roughly 400 times bigger than the moon but also about 400 times away from the earth. This makes it look as if the moon is about the same size of the sun. In a total eclipse it can seem to be completely blocking it when viewed from earth.
If you were lucky enough to be in the Faroe Islands during this eclipse, you would have had the opportunity to experience a total eclipse, which lasted two minutes and 47 seconds.
When one reflects on the fact that the last total solar eclipse visible from Malta happened over 1,400 years ago, on August 12, AD 603, one realises that witnessing such an eclipse is by no means an everyday occurrence.
But 145 years ago, our great-grandparents were treated to the next best thing, a deep partial eclipse, where the moon covered 99 per cent of the sun. They would have experienced a darkening of the skies and a game of shadows the likes of which we might witness again in 12 years’ time when the next almost-total eclipse will be visible from Malta.
An eclipse, partial or not, can be directly viewed only with the right eye protection.
Some people opted for the easiest method of using special eclipse glasses, which are cheap to buy. Others might have gone for an arc-welder’s glass shield, which must have a shade of #14 or more to be safe.
The safest method was to watch the sun’s image projected onto a piece of paper using the pinhole method. Interestingly enough, an eclipse can be viewed even through the shadow of a kitchen colander by holding it with your back to the sun and projecting multiple small eclipse images onto a paper.
Tree shadows can also act as pinholes and project a number of eclipse images onto the ground.
Those lucky enough to be able to view the eclipse through a telescope or binoculars could only do so by using special filters which would prevent over 99 per cent of the sunlight from entering the instrument and damaging one’s eyes.
If you missed the partial solar eclipse, make sure you do not miss watching the moon eat away at a tiny bit of the sun in June 2020. Then on August 2, 2027, the date of the near total eclipse, you will have a more spectacular experience.
But the most spectacular will only be viewed by those lucky enough to still be alive on April 21, 2088, the date of the next total eclipse visible from Malta.
To see photos of this year’s partial eclipse taken by some of our members visit the Astronomical Society of Malta’s Facebook page.
www.maltastro.org/blog
Astronomical events in April
Wednesday: Moon at apogee, 406,000km away.
Saturday: Full moon at 2.06pm.
April 8: Moon close to planet Saturn (morning sky).
April 11: Venus close to the Pleiades star cluster (evening sky).
April 12: Last quarter moon at 5.44am.
April 17: Moon at perigee, 361,000km away.
April 18: New moon at 8.57pm.
April 21: Moon close to planet Venus at 8.09pm (evening sky).
April 26: First quarter moon at 1.55am.
April 29: Moon at apogee, 405,100km away.
Alexei Pace is president of the Astronomical Society of Malta.