The Grand Eclipse Expedition of 2023
Richard (Rick) Tonello
Chief Astronomer GDC Observatory
On the 20th April 2023, along the sun drenched coastline of the Cape Range National Park, the Solar System will put on a spectacular show that will attract tens of thousands of people from across Australia and the world.
This celestial event will showcase the precision clockwork of the Solar System as the Sun, Moon and Earth perfectly align to create the spectacular phenomenon known as a Total Solar Eclipse.
Starting in the Great Southern Ocean, the shadow of the Moon will race across the surface of Earth at over 2700Km/h, skim over the Exmouth Peninsula and race northward from the Australian continent toward Timor-Leste and the Pacific Ocean.
For people along the narrow “Line of Totality” they will witness the Moon completely cover the blinding disc of the Sun revealing the complex structure of the Solar Corona. For a brief 62 seconds, observers will be plunged into an eerie twilight and the sky looking like a bullet has pierced its familiar continuum.
While there is a Total Solar Eclipse every 18 months somewhere around the world, this eclipse is special. The 2023 event is a rare Hybrid Eclipse that occurs once every decade. A Hybrid Eclipse is where the distance between the Earth and Moon is so finely balanced, that the curvature of Earth influences how much of the Moon covers the disc of the Sun. From the starting point in the Great Southern Ocean any observers will see an Annular Solar Eclipse, from Exmouth observers will see a Total Solar Eclipse.
Astronomers from the Gravity Discovery Centre Observatory will be on an expedition to Exmouth to observe, photograph and live stream the entire Total Solar Eclipse from the line of totality.
Live images will be provided from two, specialised Solar Telescopes and high-resolution cameras. One telescope will observe the Photosphere (Light Sphere), the surface of the Sun, while the other telescope will observe the Chromosphere (Colour Sphere), the dynamic layer located above the photosphere.
The broadcast provided by the GDC Total Solar Eclipse Expedition will be broadcasted to their FaceBook Page and YouTube Channel.
Local Media, social media and other organisations will pick up the GDC Observatory Total Solar Eclipse broadcast on the day of the Eclipse. Organisations such as Tourism WA, the Museum of Western Australia, the Singapore Science Centre, and to the Yagan Square Multimedia Screen are just a few of the organisations to utilise the live stream.
Those who are not observing from the Path of Totality will observe a Partial Solar Eclipse. Depending on the distance of the Observer from the path of Totality, the less of the Sun’s blinding disc will be obscured by the Moon.
Observers from Perth will witness a little over 70% of the Sun’s disc obscured by the Moon. Even though a majority of the Sun’s disc is covered, it is still dangerous to observe without the proper eye protection. Never look directly at the Sun, even during the Partially Eclipsed phases. Even a 99% obscured Sun is enough to cause Solar Retinopathy (irreversible eye damage). Always use approved Solar Viewing Equipment (Eclipse Glasses) with the ISO 12312-2:2015 markings.
There are many ways to enjoy the Partial Eclipse through indirect viewing such as Pin-hole cameras, Camera Obscuras, kitchen colanders and Live streaming services.
There are many sources of information regarding Safe techniques to observe the Total and Partial Solar Eclipse such as the NASA, Gravity Discovery Centre & Observatory and Astronomical Society of Australia websites.
Through public education and correct information, let’s make this a date to remember for all the right reasons.