Anyone that enjoys watching otherworldly astrological events unfold across the night sky would be wise to look up this evening, because today's winter solstice is set to also see the culmination of the "Great Conjunction" — when Jupiter and Saturn come together to form the visible and bright "Christmas Star."

The phenomenon of Jupiter and Saturn gradually travelling through the sky has been visible in Toronto's evening skies for the past two weeks, with the peak expected for tonight as the former appears to catch up to and overtake the latter. 

"You can imagine the solar system to be a racetrack, with each of the planets as a runner in their own lane and the Earth toward the center of the stadium," said astronomer Henry Throop in a NASA blog post. 

"From our vantage point, we'll be able to be to see Jupiter on the inside lane, approaching Saturn all month and finally overtaking it on December 21."

Skywatchers, you're in for a once-in-a-lifetime treat! Jupiter & Saturn are doing a planetary dance that will result in the Great Conjunction on Dec 21, just after sunset. Find out:

🤩 When and where to look up
📷 How to photograph the conjunction

Visit: https://t.co/SdQSLex2Ex pic.twitter.com/DkaB5XyO9B

— NASA (@NASA) December 20, 2020

According to NASA, the planets often appear to pass each other in our solar system, and Jupiter and Saturn align in the sky roughly once every 20 years. 

What makes tonight so special, then, is the fact that it's been nearly 400 years since the two planets moved this close to one another, and nearly 800 years since it happened at night — making it visible to the naked eye.

"On the 21st, they will appear so close that a pinkie finger at arm's length will easily cover both planets in the sky," according to NASA. 

But while the two planets will appear extremely close together from the perspective of a human being looking up to the sky, in reality, Jupiter and Saturn will remain hundreds of millions of miles apart in space. 

And the fact that this "Christmas Star" will be visible on the night of the winter solstice is also merely a coincidence, according to NASA.

"Conjunctions like this could happen on any day of the year, depending on where the planets are in their orbits," said Throop.

"The date of the conjunction is determined by the positions of Jupiter, Saturn, and the Earth in their paths around the Sun, while the date of the solstice is determined by the tilt of Earth's axis. The solstice is the longest night of the year, so this rare coincidence will give people a great chance to go outside and see the solar system."

If you're hoping to head outside and catch a glimpse of the "Great Conjunction" tonight, be sure to find a spot with an unobstructed view of the sky, such as a park or field, according to NASA. 

The space agency says skywatchers should look to the southwestern sky approximately one hour after sunset, which is set to occur at 4:43 p.m. in Toronto. 

And while the planets will be visible to the naked eye, including from most cities thanks to their extreme brightness, using binoculars or a small telescope may also provide a view of Jupiter's four large moons orbiting the giant planet.