How and when to watch the rare total solar eclipse

At precisely 11:27am Western Australia time, the sun, the moon and the Earth will align to create a total solar eclipse.

The path of totality - the track of the moon's shadow across Earth's surface - will graze the tip of Western Australia in a 40-kilometre wide track near Exmouth, making it the most accessible land-based place on Earth to view the spectacle.

The process of the moon moving across the face of the sun takes approximately 3 hours.

The small coastal town of Exmouth is preparing for an influx of visitors keen to stand in the shadow of the moon.

The event will be a boon for the town of just 2,806 people as Tourism WA predicts more than 10,000 visitors will head to Exmouth and surrounding areas to witness the solar eclipse event that happens on any one part of Earth only every 400 years or so.

Astrotourism WA CEO Carol Redford said witnessing a solar eclipse was an unforgettable experience.

"It was incredible, my key memories are how the temperature dropped, as the moon starts to cover the sun, because its blocking out all of that light, it got noticeably cooler.

"I wasn't prepared for that. You can physically see the moon's shadow coming across the earth towards you," she said of her experience watching the 2017 United States solar eclipse.

"You can see the corona, the outer atmosphere of the sun, it looks like oil on water. It's beautiful.

"Anyone travelling up to Exmouth for the total solar eclipse will see Jupiter and Venus, they will appear in the eclipsed sky," she said.

The picturesque Coral Coast town sits alongside the UNESCO World Heritage-listed Ningaloo Marine Park, where the famous whale sharks will be visiting as the eclipse takes place.

The region has benefitted from almost $22 million in funding to help ensure readiness for a significant increase in visitors, including grants totalling more than $837,000 for 40 local Gascoyne and Pilbara businesses.

Pink Floyd has even offered eight lucky fans the chance to view the eclipse in person while listening to their iconic album Dark Side of the Moon to celebrate the 50th anniversary of the album.

University of Melbourne associate professor of physics Christian Reichardt said spectators will experience a sudden change in light and the optical phenomenon known as 'Baily's beads' or the diamond ring effect will occur.

As the last of the Sun disappears behind the Moon, the final rays of sunlight pass between the rugged edge of the moon and shine through in some places while not in others, creating a diamond-like effect.

Professor Reichardt warned against looking directly at the eclipse.

"You never want to look at the sun with naked eyes. The options are you get eclipse glass with filters or glass that will allow you to safely look at the sun. They're not super expensive, but you need to make sure you use it when looking at the sun," he said.

"If you're staring at it when the sun blinks out you can damage your eyes."

Solar eclipses occur around once every 18 months visible from somewhere on earth, but they only recur at any given place only once every 360 to 410 years.

Light pollution increases each year and for many city residents seeing a star in the sky is a rare occurrence.

Carol Redford wants to put Western Australia on the map as a hot spot for astrotourism.

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"Light pollution is an increasing problem around the world, it's increasing by at least 2 per cent every year, so we're losing the view of our night sky," she said.

"As the scourge of light pollution increases, some people in cities never see one star, and you come out to western Australia and you can see hundreds of billions of stars in the milky way."

Indigenous Australian astronomy will be celebrated as part of a series of events leading up to the Ningaloo eclipse.

The coastal people of Ningaloo Baiyungu, Yinnigurdira and West Thalanyji have a deep connection with Wilarra (Moon). It has historically guided when is the best time for fishing, hunting and it is a guide for the tides.

Aboriginal Australians were careful observers of the night sky and possessed a complex understanding of the movements of planets, the moon and the sun and their relation to earthly events.

Researchers from Macquarie University found that some First Nations groups may have understood the mechanics of the Sun-Earth-Moon system and the relationship of lunar phases to events on the Earth.

The Exmouth Peninsula, Timor Leste, and West Papua are the only places in the world that will experience a total solar eclipse. However at least a partial phase of the eclipse will be visible from the southern Indian Ocean, parts of Antarctica, most of Australia, Indonesia, Philippines, most of Oceania, Southeast Asia, and the western Pacific Ocean.

The Perth Observatory will be live streaming the eclipse for approximately three hours, with the peak occurring around 11:27 am Western Australian time.

Partial coverage will be visible around Australia, with the best view in Western Australia and the Northern Territory. Southern states will have a limited view. Here's when to look up (with sun protection on) on April 20, according to Time and Date: