Home > News and views > View all

The partial eclipse – a guide to safe viewing and teaching resources

Published: Mar 12, 2015 5 min read

James de Winter

What are you doing on the morning of Friday 20 March?


I hope by now that you know the answer to this question. Equally I hope that your answer is not “run screaming from the fields thinking that a giant monster is eating the sun and that the world is about to end”. It’s easy to joke that those who saw eclipses as terrifying, inexplicable things that signalled the end of the world as fools but it’s not that unreasonable when you consider that the sun going dark, without warning is quite a remarkable and in many cases, once in a lifetime experience.

It’s quite a testament to the power of science and the predictability of the solar system that we can know, with such precision what will happen and when.

For us in the UK, we are likely to have close to 90% of the sun blocked by the moon at around 9:30am. The sun will be quite low in the sky but it’ll still be pretty impressive to say the least if the sky is clear and if viewed safely (see note below).  Some will remember the 1999 eclipse, where parts of Cornwall experienced a full solar eclipse and if Friday goes badly then the younger amongst us can wait until 23 September 2090 when parts of the south of UK will have another full solar eclipse. For the rest of us, the 20 March represents a significant opportunity to remind us of the awe and wonder and the magic of the universe that probably got many of us into science and teaching in the first place. I will also point you in the direction of some teaching resources and an off the shelf presentation that you could use in school.

Viewing the eclipse safely

Much has been written elsewhere about the eclipse and this can all be easily found – so all I’ll say is that it’d be a real shame if we weren’t all able to do something that morning. Instead, here are a couple of interesting eclipse based facts that you might not know, to throw into conversation on 20 March.

Hopefully everyone realises how dangerous it can be to look directly at the sun with anything other than specifically designed glasses or a viewer. You simply must not do it.  The National STEM Centre has full details of ways to look at the eclipse safely, this is one of the resources originally from the Royal Astronomical Society.

Solar eclipse interesting facts

Halley did more than name a comet

Edmond Halley is perhaps most famous for his comet, last seen in 1986 and next due to be visible in 2061 reminding us that we sometimes need patience to be an astronomer. He predicted with impressive accuracy the full solar eclipse that cast a shadow across most of Southern England on 3 May 1715. That eclipse lasted three minutes 33 seconds and he managed to get its location within 30 miles and he was only four minutes out. Not bad for a world without calculators.

The Mountains of the Moon, beads and diamonds

Whilst we won’t see a full solar eclipse here in the UK, if you did it would be possible to see a rather amazing phenomena called Baily’s Beads. As the moon moves in front of the Sun and blocks out the light, because the surface of the moon is not completely smooth at certain points the sunlight can pass through some parts of the edge of the moon and in other places not, causing ‘beads’ of light to appear where the light can pass. At one point as the total eclipse is almost formed, where there is only one of these beads, you can observe an effect called a diamond ring – where there is just one bright bead of light and a ring around the silhouette of the moon making it look just a, you guessed it, diamond ring.

Solar eclipse presentation for your classroom

David Smith from Highgate School and The Institute of Physics (IOP) produced a great slideshow that draws together some great images that are freely floating around the internet. Some with more detail of the 1715 eclipse; where you might see the total eclipse (if you avoid the polar bears) and a look at where and when the next ones will be. It’s available on the Triple Science Physics community group on the National STEM Centre Website. You need to register to get at the files but it’s free, quick and easy to do so.

 More astronomy resources

If the eclipse stirs your or some of your students interest then, when logged into the community, there are more astronomy resources in astronomy topic in the physics group:

There is also a separate astronomy community group managed by Tom Lyons ESERO Teacher Fellow that is open to all and has more riches.

A complete history of stars and space in a few hours

If you want to get up to speed on the history of astronomy from the Greeks to the moon landings in a few hours then I’d suggest that the best place to start is the booklet Stars and Forces from the  National STEM Centre eLibrary. It’s a really easy read, written ever so well by Joan Solomon and is possibly the single best primer on space, gravity and the progression of thought and ideas on space I’ve read. Highly recommended.

Further eclipse references:

How to observe the partial eclipse on March 20” from the Society for Popular Astronomy

Preparing your school for the solar eclipse” from The ASE

The Met Office’s event page

The National STEM Centre will be hosting the EU’s Scientix conference in York in April 2015. One of the sessions will be led by ESERO fellow Tom Lyons who will be providing activities, resources and ideas around using space as an inspiring teaching theme for primary and secondary teachers. This is a free conference, totally funded by the European Union.