How to catch the 'Great Conjunction' of Jupiter and Saturn in the Halifax area On Dec. 21, the solar system's two largest planets will be the closest they've been in 800 years Dec 16, 2020 1:45 PM By: Meghan Groff It's called the Great Conjunction. On Dec. 21, the solar system's two largest planets will be the closest they've been in 800 years. "This is the first time Jupiter and Saturn have been this close since 1226," explained Saint Mary's University astrophysics professor, Dr. Rob Thacker. "If you go back that far, of course there were no telescopes then, s...