A century after scientists used a solar eclipse in WA’s remote north to prove Einstein’s most controversial theories, astrophysicists were back to learn more.

April 20, 2023

The mystery of the sun will be further revealed as scientists delve into data recorded during a rare total solar eclipse in Western Australia’s remote north.

It comes just over a century after astronomers and astrophysicists used an eclipse on the same coastline to prove one of Albert Einstein’s most controversial theories.

This time, the total eclipse fell across the North West Cape at 11.29am AWST (1.29pm AEST) when the moon completely blocked the sun for about a minute, allowing scientists to further their knowledge of the sun’s outer atmosphere and temperature.

Temperatures dropped and day turned to night, revealing stars and a halo of bright light behind the moon as it fell into perfect alignment with the sun.

For many scientists it was a moment to further their understanding of the solar system.

Perth Observatory’s Matt Woods told AAP the eclipse provided valuable data about the sun as it approached solar maximum.

“The sun is becoming a lot more active, we could clearly see solar prominences and sun spots,” he said.

“They’re massive tears in the surface of the sun because of magnetism.”

Mr Woods said the information captured would help astrophysicists further their understanding of the sun’s corona or outer atmosphere, which expands into the solar system.

Flares of plasma caught in magnetic field lines were visible during the eclipse and would be of great interest to the scientific community.

“It’s amazing to be able to see part of the sun you can’t normally see. It’s the only planet and moon on the solar system that you can see the corona,” he said.

In 1922 a group of Australian and international astronomers, naval men, and Aboriginal stockmen transported a telescope from Perth to a remote spot on the WA coast north of Port Hedland.

It was there, during a total eclipse that September, they proved Professor Einstein’s controversial ‘Theory of General Relativity‘.

Published seven years earlier, the paper documented the famous physicist’s ideas and understanding of how gravity works.

WA Chief Scientist Peter Klinken said the 1922 eclipse gave the scientists, using a telescope that now resides at the Perth Observatory, an opportunity to measure the way light coming from stars bent around the sun.

Fast forward a hundred years and a new generation of astrophysicists and astronomers studied a total eclipse.

“It was a real wow moment,” he said.

“One of the things I noticed was a thing called ‘Baily’s Beads’ which is a brief moment when the sun is just peaking through and you can see these little beads going around it.

“That’s hills and crevices on the moon.”

Gravity Discovery Centre and Observatory chief astronomer Rick Tonello helped stream the eclipse around the world to scientific institutions and platforms.

‘It was prime moment to look at the corona of the sun, the constant out-streaming of charred particles that form the solar wind,” he said.

“The corona is a large structure that surrounds the sun and what we saw was the complex magnetic fields generated from the interior of the star.”

The sun’s surface temperature was about 5,500C but the corona was about a million.

“There’s a huge discrepancy. Why is there a big temperature difference?” he said.

“So this is one way we can study the magnetic field, the actual temperature, the structure, the streaming of the particles.”