Document Type


Publication Title

The Mathematical Gazette

Publication Date



[In lieu of an abstract, an excerpt from the introduction is presented]:

On 21 December 2020 the night sky offered a beautiful astronomical treat for stargazers worldwide. An exceptionally rare conjunction of Jupiter and Saturn brought them to 0.1 degrees of angular separation – a fifth of the full moon's diameter. It marked their closest approach since 1623 and the closest visible conjunction since 1226 (almost 800 years ago!). Astronomy enthusiasts crossed their fingers for clear skies and waited eagerly for this event. The internet and social media were inundated with pictures and news reports, celebrating the great conjunction of our solar system's two most extensive and majestic planets. The author was fortunate to have clear skies to enjoy this rare celestial event. He saw these two planets in the same telescopic field of view for the first time.

Funding Source

This article was published Open Access thanks to a transformative agreement between Milner Library and Cambridge University Press.


First published in The Mathematical Gazette , 107, no. 570 (November 2023): 422 - 429.

This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives licence (, which permits noncommercial re-use, distribution, and reproduction in any medium, provided the original work is unaltered and is properly cited.


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Mathematics Commons