“If you have very good eyesight, you’ll still be able to make out the two planets, but to most of us it will appear as one object,” Professor Horner said.
For stargazers professional and amateur alike, it will be an added spectacle, with both planets clearly visible through a single telescope frame.
“For people with even small telescopes they’ll be able to get both planets in the same field of view at the same time, which will be breathtaking,” he said.
“I’m expecting some really otherworldly, almost science-fiction type images to come out of it, with Saturn’s rings and Jupiter’s moons, it’s going to be incredible.”
The last time the planets aligned like this was in 1226, when Genghis Khan was consolidating power across large swathes of Asia.
Professor Horner said even though it had been a long wait to see the celestial event, it would not be nearly as long until the next chance.
“Jupiter and Saturn enter the same region of the sky every 20 years, but 20 years ago they weren’t as close as they are now,” he said.
“Sixty years from now they’ll come back to the same configuration as they are this year, so some of us who see it this year might still be around in 2080 to see it again.
“But after that it’s another long wait for the next one.”
Some scientists have suggested a convergence of Jupiter and Saturn may actually be the inspiration for the biblical Star of Bethlehem referenced in the Gospel of Matthew, while others have suggested a comet or even a supernova might have inspired the biblical story.
Professor Horner doesn’t ascribe special significance to the phenomenon, but said the beauty of the solar system as it wheeled through space was enough.
“I’m not expecting the continents to crumble and the world to shake, but it is something beautiful,” he said.
The conjunction comes after the annual Geminid meteor shower, which will reach its height late this weekend about December 13 to 14.
The annual meteor shower is usually the most spectacular of the year, meaning the conjunction will serve as a spectacular cap to the annual display.
Stuart Layt covers health, science and technology for the Brisbane Times. He was formerly the Queensland political reporter for AAP.