A once in a lifetime opportunity will occur in the sky tonight, as Jupiter and Saturn align in the “Great Conjunction”.

Matt Woods from the Perth Observatory told 6PR’s Michaela Carr “The great conjunction is when Jupiter and Saturn get very close together.”

“This usually happens every twenty years or so, but the reason why this one is extra special is because they are within point one of a degree,” he said.

The planets will be so close they will appear as a single bright star in the night sky.

“They haven’t been seen this close since 1623 when Galileo was still alive,” he said.

“If you have a look with your naked eye you’ll just see one star, but you’re actually seeing two planets.”

A number of different astronomical groups in Perth will have telescopes available for viewing at Perth beaches tonight, including North Coogee, Burns Beach, and Scarborough.

“If people can’t make it we are going to live stream it on our YouTube.”

The best time for Perth stargazers to view the Great Conjunction is between 7.45pm to 8.30pm.

Click play to hear the full interview. 

(Photo: iStock by Getty Images.)