TORONTO -- Monday鈥檚 winter solstice date will bring about an astrological event known as a 鈥済reat conjunction,鈥� when gas-giant planets Jupiter and Saturn will appear to align in the sky and create an ultra-bright 鈥淐hristmas Star.鈥�

鈥淛upiter and Saturn, they鈥檙e separated by hundreds of millions of kilometres but from our vantage point they will look like beads on a string, and they will get within one tenth of a degree tonight鈥echnical term, they鈥檙e going to kiss in the night sky,鈥� said York University astronomy professor Paul Delaney on CTV鈥檚 Your Morning Monday.

While great conjunctions occur almost every 20 years, the last time Jupiter and Saturn were this close to one another was in 1623. And it just so happens to land on the winter solstice this year

However, Delaney pointed out that the 1623 great conjunction was very close to the Sun, and therefore unlikely to have been visible 鈥� meaning the last time a great conjunction like Monday鈥檚 Christmas Star visible to the naked eye would have been close to 800 years ago in 1226.

鈥淭his is an event not to be missed because it鈥檚 another 400 years before they [Jupiter and Saturn] get this close again,鈥� Delaney said.

If skies are clear, Canadians should be able to see the Christmas Star from 4 p.m. to 6 p.m. EST -- 鈥渁 hand span above the horizon in a southwestern sky鈥� -- Delaney said, before it passes too far west and out of sight.

According to NASA, those wishing to see the phenomenon should head outside around 45 minutes after sunset and try to find a clear line of sight towards the horizon where the sun went down鈥� it doesn鈥檛 have to be fully dark outside for the great conjunction to be visible.

Jupiter will look like the brightest star in the sky, with Saturn slightly above and to the left.

For Delaney, the excitement is palpable.

鈥淭his is like game seven of the Stanley Cup in triple overtime,鈥� he said.

York University will be running a livestream event on YouTube starting at 4 p.m. EST and will broadcast live pictures of the phenomenon and answer questions.

You can find more information on the great conjunction, and how to watch it, from .