by Dr Catriona Nguyen-Robertson MRSV

This piece appears in the April 2023 edition of Science Victoria magazine. All issues can be read online for free at rsv.org.au/Science-Victoria.

This article follows the Eclipse Chasers book launch, hosted by the Royal Society of Victoria (RSV), the Astronomical Society of Victoria (ASV), and CSIRO Publishing on 14 March 2023.

Joining the authors, historian Dr Toner Stevenson and astrophysicist Prof Nick Lomb, were Dr Tanya Hill (Senior Curator in Astronomy at Museums Victoria), Mark Iscaro (ASV President) and Dr Robin Hirst (formerly Director Collections Research and Exhibitions at Museums Victoria) for a discussion facilitated by Mike Flattley (RSV CEO).

‘Witnessing a total solar eclipse is a wondrous and unforgettable event,’ – so says the blurb of Dr Nick Tomb and Dr Toner Stevenson’s latest book, Eclipse Chasers.

If you ever get the chance to see a total solar eclipse, Dr Robin Hirst, who was Director of Collections, Research and Exhibitions for Museums Victoria for almost two decades, recommends standing high up and looking down below. The shadow of the Moon races across the Earth at around 1 km/s. Then, a ‘diamond ring’ of the Sun’s crown shines once the rest is blocked out. Even if you do not observe the eclipse itself through the clouds, it is magical. Dr Toner Stevenson recalls hearing birds stop chirping, seeing horses huddle together, and flowers close up as the Sun disappeared.

Eclipse Chasers showcases the drama and beauty of total solar eclipses and is essential reading for anyone fascinated by these amazing events. The book, written by Dr Toner Stevenson from the University of Sydney and Professor Nick Lomb from the University of Southern Queensland, unveils First Nations knowledge, previously hidden contributions from women, and past expeditions to chase eclipses. It also looks forward, so that you can prepare your celestial view for the next two decades of Australian eclipses.

What is an eclipse?

‘Eclipses are all about shadows,’ says Dr Tanya Hill, Senior Curator, Astronomy at Museums Victoria. Whether it is the Earth’s shadow on the Moon for a lunar eclipse, or the Moon’s shadow on Earth for a solar eclipse. When the Moon passes between Earth and the Sun, thereby totally or partially obscuring our view of the Sun, we witness a solar eclipse. It happens due to ‘crazy coincidence: the Moon is 400 times smaller than the Sun, but it’s also 400 times closer’. This means that, from Earth, the Moon and Sun appear to be roughly the same size in the sky, and the Moon appears large enough to block our view of the Sun. The Moon does not cast a shadow over the entire Earth at once, but rather, is seen over a particular spot.

The Sun is enveloped by a corona, or crown, which is its outermost atmosphere. The corona is usually hidden – or rather drowned out – by the bright light of the Sun’s surface, but it can be seen during a total eclipse. A view of totality from Australia is rare, having occurred only five times last century. However it is predicted to occur more frequently in this century – five times in the next 17 years alone. Nick and Toner have travelled the world chasing eclipses, and their book outlines how we can too.

Tanya remembers staring at her feet in the school yard for assembly during the 1984 solar eclipse. The students were somewhat ominously told that something was happening to the Sun, but they were not allowed to look. Similarly, RSV CEO Mike Flattley’s parents had drawn all the blinds in the house in preparation for an eclipse and encouraged him to hide under the bed. But when you do look at a solar eclipse – with all the proper safety precautions – they are incredible. Mike is now out from underneath the bed, and excited to learn how to witness an eclipse thanks to Eclipse Chasers, and share this experience with his children.

A legacy of eclipse chasers.

With continuous observations of the sky over tens of thousands of years, the First Peoples were the first astronomers of these lands. The rare, brief total solar eclipses are well known in the knowledge systems of Aboriginal and Torres Strait Islanders, who have witnessed them hundreds of times over millennia. They knew that it was the Moon that blocked the Sun – and that this would only ever happen during a New Moon. A/Prof Duane Hamacher and Uncle Ghillar Michael Anderson, Senior Law Man, Elder, and leader of the Euahlayi Nation, contributed a chapter to the book, detailing the eclipses embedded within First Peoples’ knowledge and traditions.

The total solar eclipse of December 1871 was the first eclipse Nick researched and remains his favourite. The RSV President at the time, Robert L. J. Ellery, led an expedition of astronomers from Melbourne and Sydney to Cape York to view it. While the overcast weather meant that they were unsuccessful in observing the eclipse, it is an important event in Australia’s scientific history (and the party at least returned with botanical specimens and meteorological observations to show for the journey).

As a woman who has experienced six (and hopefully soon, seven) total solar eclipses, Toner has been inspired by women who have come before her. Women would accompany eclipse expeditions, and they were certainly not merely along for the ride. The trips were long and gruelling, and the women who went (often wives, daughters, or friends of the other expeditioners) brought their own expertise and skill sets. Annie Dodwall measured the drastic change in temperature during the 1910 eclipse, Miriam Chisholm and Freda Tindell wrote detailed reports, and Elizabeth Campbell operated the camera and spectrographs in 1922. Toner tells the adventures and contributions of these often overlooked women in the book.

The Astronomical Society of Victoria encourages everyone to observe the sky. Its president Mark Iscaro images the sky with his phone attached to a standard backyard telescope to prove that we can capture good photos without tens of thousands of dollars’ worth of equipment. However, highlighting our disconnect with the sky (compared to First Peoples who are keen observers of the sky and have detailed knowledge systems built around the Sun and Moon), he notes the stark contrast between star gazing in the city and “dark sky sites” away from light pollution. He encourages us to reignite our enthusiasm for the stars in the sky as a society.

It is difficult to capture the beauty and emotion of watching an eclipse in a book. Even in the Melbourne Planetarium, located at Scienceworks, Tanya can show an audience an eclipse in the 360° dome, with music to evoke emotion. However, having witnessed one in real life, she knows that it is not quite the same. Over a period of 17 years, solar eclipse fans can view five more eclipses under Australian skies. Enthusiasts worldwide will flock to Exmouth in Western Australia on 20 April this year to catch the best view of a total solar eclipse. After reading Eclipse Chasers, you too could catch, to quote Science Programs Manager at Museums Victoria, Kate Barnard, ‘the dance of these celestial bodies’.

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Eclipse Chasers by Nick Lomb and Toner Stevenson (CSIRO Publishing, ISBN: 9781486317073) is available now in paperback and eBook versions. Details at publish.csiro.au/book/8098/