August's Eclipse:- What to Expect

THE FACTS

Right then, most of you by now will have heard about it from somewhere or other. But how much do you really know about 1999's eclipse? Read this to find out all you need to know about what to expect (apart from the supposed 'End of the World' that some people have predicted).

This eclipse will be the first eclipse visible from the U.K. mainland since 1927- 72 years ago! If that sounds daunting, guess when the next one is! 2090!! We'll have to wait 91 YEARS to see the next one from the U.K. (most of us won't see it; I'll be 106 when the next one occurs in Britain- assuming I live that long!). But that shouldn't worry us. We've still got this one to go!

Back to the present, where will the moon's shadow fall? Where will the eclipse be visible from? CORNWALL! Well, obviously that's not the only place, but it's the best place to be to see the TOTAL ECLIPSE! Before I explain this in more detail, you need to know this: during an eclipse, the moon's shadow, or UMBRA, only covers a very small portion of the globe- about 1/2%! This should tell you that only a very small area will experience the total eclipse.

A map of the eclipse of 1999 and partial eclipse magnitudes. Taken from http://www.eclipse.org.uk

This map shows the different magnitudes of the eclipse across the country. The dark grey band is where the moon's shadow will fall directly. This area is called the umbra. Anyone within the umbra will witness a total eclipse (Unless we are unlucky and only see an ANNULAR ECLIPSE). The centre line of the band, called the 'LINE OF TOTALITY', is where the eclipse will last longest. As you move towards the northern or southern LIMITS OF TOTALITY, the duration of the eclipse will become reduced. Beyond the limits of totality (called the PENUMBRA) you would not see a total eclipse- you would see a PARTIAL ECLIPSE.

The best town to be for the eclipse would be Falmouth. The centre line of totality runs right through it, and the eclipse will be total for about 2 minutes there. But even at the limits, totality (totality- sounds like a 'Mortal Kombat' death move, doesn't it?) can be observed for 1 minute 39 seconds. With the northern limit running through Port Issac, anyone near there should see a reasonably lengthy eclipse.

"But what about the rest of us?" you ask, "What will we see?" Well, it depends on how far away you are from the limits. If you are really close to where the limit will be, you will see an almost total eclipse, with about 95+% of the sun covered (and if you're feeling athletic, you could have a run down to the limit to see the full one- or you could drive if you're lazy like me!), and as you go further and further away from the limit, less and less of the sun will be blocked by the moon, and in some places, no eclipse will be visible at all!

If you look back at the map, the little pictures on the right of it indicate the degree, or MAGNITUDE of the eclipse. look for the one that corresponds to your area, and the picture will show you the fullest eclipse possible for that area. Even if you're not lucky enough to see the total eclipse, even a partial eclipse is an event not to be missed! SO MAKE SURE YOU DON'T! (Unless you're planning on catching the next one...).