Early risers are in for a celestial treat this weekend when four planets in our solar system align in a rare event.

Australian National University astrophysicist Dr Brad Tucker said the phenomenon was unique as Saturn took 29 years to orbit the Earth, with the last similar alignment in 2002.

"Saturn is on top, followed by Mars, third is Venus, which is super bright, followed by Jupiter, and then you have the moon as the fifth celestial wheel," Tucker told Gareth Parker on 6PR Breakfast.

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