April’s total solar eclipse over Ningaloo: the first of five for Australia

Scientists and eclipse enthusiasts available for interviews: contact Tanya Ha at Science in Public on 0404 083 863 or tanya@scienceinpublic.com.au

Images below

At 11.29 am AWST on Thursday 20 April 2023 the sun will disappear over Ningaloo. It will reappear a minute later.

The rest of Australia will experience a partial eclipse, and a chance to prepare for the big one, a total eclipse over Sydney in 2028.

“Our last total solar eclipse was in November 2012, with Cairns right in the path of totality,” says amateur astronomer and eclipse chaser Terry Cuttle. “It’s been over a decade’s wait for another Aussie eclipse, so I’m on my way to Exmouth and Ningaloo – I wouldn’t miss it for the world!”

Map showing the path of totality of the next five solar eclipsed obeservable from Australia. — Map showing the paths of totality for the next 5 total solar eclipses viewable from Australia. Credit: Astronomical Association of Queensland/Terry Cuttle. Base map: Google Earth.

“Solar eclipses are spectacular,” says President of the Astronomical Society of Australia (ASA) Professor John Lattanzio. “So, Australia really is the lucky country with five total eclipses visible in various parts of the country over the next 15 years.”

Any single location on Earth is only likely to see a total eclipse once every few hundred years.

Dr Hessom Razavi of The Royal Australian and New Zealand College of Ophthalmologists (RANZCO), and the Lions Eye Institute, warns people to, “Never look directly at the Sun. It can cause serious and permanent eye damage, and that’s true even during a solar eclipse. Children’s eyes are especially vulnerable to damage”.

According to the ASA, the best ways to observe an eclipse are through:

special-purpose ‘eclipse glasses’ or hand-held solar viewers with solar filters that meet the international standard
using pinhole projection through a large card with a two-millimetre hole in the centre to project an image of the Sun onto another surface held about a metre away.

RANZCO advises that using solar eclipse glasses still carries some risks, so people must make sure their glasses meet the ISO 12312 2 standard and that they read and follow all safety advice and precautions, ensuring that there are no scratches or other damage. According to RANZCO, the only way to guarantee the prevention of solar retinopathy is to avoid all forms of direct sun viewing.

The ASA has created a comprehensive website at eclipse.asa.astronomy.org.au including sections on:

RANZCO has prepared advice for the public which can be found at ranzco.edu/wp-content/uploads/2023/03/RANZCO-Position-Statement-For-the-General-Public-Solar-Retinopathy_2023-1.pdf

Talent available for interviews:

Prof John Lattanzio, President of the Astronomical Society of Australia (ASA; VIC)
Terry Cuttle, amateur astronomer, astro-photographer and eclipse chaser; member of the International Astronomical Union’s Working Group on Solar Eclipses (QLD)
Dr Tanya Hill, Senior Curator, Astronomy, Melbourne Planetarium (VIC)
Dr Martin George, Senior Astronomer at the Devonport Planetarium and Chair of International Development and Elections, International Planetarium Society (TAS)
Dr Kat Ross, Science Communicator and Astrophysicist, International Centre for Radio Astronomy Research and Curtin University (WA)
Dr Rebecca Allen, Co-Director Space Technology and Industry Institute, Swinburne University
Assoc Prof Michael Brown, Media and Outreach Coordinator, ASA (VIC)
Dr Hessom Razavi, RANZCO member and ophthalmologist based at the Lions Eye Institute (WA)

Background

What is a solar eclipse?

A solar eclipse occurs when the moon passes between the Sun and Earth, casting a shadow on the Earth that either partially or fully blocks the face of the sun.

Solar eclipses are rare across the Solar System. Of the 200 confirmed moons orbiting six major planets, only the Earth’s moon is the right size and distance from its planet to neatly cover and obscure the solar disk and reveal the sun’s wispy corona.

A total solar eclipse occurs when the moon completely blocks the sun. Totality – the period of time the sun is totally obscured – only lasts up to seven minutes. It only occurs on the path of totality – the narrow path of the moon’s shadow moving across the Earth’s surface.

During an eclipse, two shadows are cast. The first is called the umbra. It is the dark centre of the eclipse shadow. The second shadow is called the penumbra and is a type of half-shadow.

Although a solar eclipse of some kind occurs somewhere on Earth at least twice each year, it is only in some of these events that the moon completely covers the sun. Sometimes the umbra misses Earth altogether, passing ‘above’ or ‘below’ our planet.

Australia’s Eclipse Quintet: 2023-2038

There will be five total solar eclipses visible in Australia over the next 15 years.

The 20 April 2023 eclipse’s path of totality will pass over Australia in the Ningaloo region of WA, including the town of Exmouth.

In Exmouth, totality begins at 11:29:50 am (50 seconds past 11:29 am) AWST and will last about one minute with the eclipsed sun 54 degrees above the horizon.

All of Australia will experience a partial eclipse, the closer an observer is to the path of totality the more the sun is obscured.

After the 2023 eclipse the next four will be:

22 July 2028 crossing the Kimberley in WA, NT, southwest Qld, NSW and passing centrally through Sydney
25 November 2030 across SA, northwest NSW, southern Qld ending at sunset in southeast Qld
13 July 2037 Through southern WA, southern NT, western Qld through to pass over Brisbane and the Gold Coast
26 December 2038 through central WA, SA, and along the NSW/Vic border.

For more information, visit: eclipse.asa.astronomy.org.au