A planetary trio is set to form Monday in the early hours when Jupiter, Mars and Venus will line up for the last time until the next one in 2021.

A planetary trio refers to a grouping of any three planets inside a circle having a five degree diameter. While in our solar system, planets revolve around the sun on a single plane but on different orbits, Monday will see Jupiter and Venus coming in closer together at the east at 3:20 a.m. and will be almost half way up in the east as day breaks at 6 a.m. Jupiter will be situated slightly towards the left of Venus. The current planetary trio will be closest of these three planets and will happen again next only in January 2021, according to NYSE Post.

The speed at which these planets take varies as they orbit around the sun. Venus only takes 225 days to orbit the sun, while Mars takes two years and Jupiter takes 12 years to make its revolution. After the sun and the moon, Venus and Jupiter rank as the third-brightest and fourth-brightest celestial bodies in space. Hence, it won't be too difficult to spot this beautiful occurrence, according to Nature World Report.

And if you held a binocular to your eyes, you would also be able to see Jupiter's moons: Io, Ganymede, Europa and Callisto. The planets are millions of miles away from each other in reality, and this rare conjunction brings them together thanks to our perspective from Earth, Mashable reported.

This time of the year is the best to catch the heavens in action, since a number of rare occurrences are set to happen within the next two months. Jupiter will move above Mars and Venus on Nov. 6, while the moon will be closer to Venus on Nov. 7. You will also get to watch Saturn just after the sun sets, and Mercury will be visible just before sunrise this month. The Leonid meteor shower also occurs during mid-November, so don't forget to cross your dates!