FIU@Home: Discover the Solstice ‘Great Conjunction’

Written by Frances Farabaugh
December 17, 2020


On the longest night of 2020, there will be something in the sky that hasn’t been seen since March 4, 1226. The conjunction of two planets – Saturn and Jupiter – will be visible for the first time in nearly 800 years.

The last time this rare astronomical event occurred, the Incans were not yet an empire in their recently founded city of Cuzco. Genghis Khan, the first Great Khan of the Mongol Empire, was on his last military campaign across western Xia. In France, King Louis the IX was taking the throne and ushering in a medieval golden age for the country.

The human eyes to gaze on it did so without many of the tools we take for granted today — the telescope hadn’t even been invented yet. In astronomy, a conjunction is when two astronomical objects appear to be close together when viewed from earth.

It’s important to note these planets aren’t actually close together in space – they are still hundreds of millions of miles apart. Their orbits around the sun simply align with Earth’s in a way that the two planets appear nearly on top of each other in the night sky. The last time our solar system’s gas giants appeared this close together was 1623, but because of the position of the sun it hasn’t been visible since 1226.


On Monday, Dec. 21, our solar system’s gas giants will appear to be within one-tenth of a degree apart. Close enough, depending on atmospheric conditions and the sharpness of your eyes, they might appear as one bright object.

The biggest difference between the night sky in 1226 and now? Light pollution. The proliferation of excessive and obtrusive artificial light not only washes out the night sky, making star gazing and astronomical research more difficult, but also disrupts ecosystems while negatively impacting on our own health.

Though the darker sky of the early 13th century would have made the event far more visible, individual human eyes also play a role.

If you want to see this phenomenon at home, you don’t need a telescope. You will just need an unobstructed view of the southwestern sky in the hour after sunset. The conjunction will appear low on the horizon.

If you’d rather watch the rare event from the comfort of your living room, you can join us for a Winter Solstice Virtual Star Party, featuring a guided viewing of this rare event led by James Webb, FIU astronomer and director of the Stocker AstroScience Center, from the home of South Florida’s only research-grade telescope (weather permitting). Space is limited – RSVP today to receive more details.


For many, this celestial phenomenon will evoke the iconic image of the Star of Bethlehem or the “Christmas Star.” You might enjoy pairing this rare sight with some holiday listening favorites. The following yule-tide tunes give the star (or stars) a brief mention and may be worth adding to your stargazing playlist:

If you are already tired of hearing holiday hymns, you can always cue up Webb’s music. He also recommends musician Muriel Anderson, particularly:

  • Nightlight Daylight
  • Eclipse

Be sure to share your favorite holiday stargazing playlist for this once in a lifetime event with us on social media @FIUCASE.

With South Florida’s only research-grade telescope, the Stocker AstroScience Center provides stunning views of stars clusters, galaxies, planets, moons and more. Follow FIU@Home for more self-guided journeys through the universe.