In late December 2020, the two largest planets in our Solar System, Jupiter and Saturn, will be so close in the sky that they’ll both be visible through a telescope eyepiece at the same time. Such close passes are known as Great Conjunctions.
The Great Conjunction of 2020 will be the closest in almost 400 years. This video gives an historical perspective to the 2020 Great Conjunction. I tell you what Great Conjunctions are, and about the what sets the periods between Great Conjunctions and the patterns that occur between successive Great Conjunctions. I discuss the Great Conjunctions of the 21st and 20th centuries, and the Great Conjunctions of 1623, 1563, 1226, and 7 BC. For example, did Galileo observe the Great Conjunction of 1623 using his telescope?