He did this to point out your apparent incorrect caption of a waxing moon in Rio de Janeiro.

ECONOMIST: Letters

Only days earlier, the courtroom had seen humor in the question of whether jurors would understand references to a "waning" or "waxing" moon.

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The Waxing Gibbous Moon - the lunar phase between first quarter Moon and a full Moon - will be approximately one degree south of Jupiter appearing to be only a pen width apart.

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Unfortunately, his mnemonic would only work in the northern hemisphere, where the moon is observed in the southern sky with the right side of the moon sunward during the waxing phase and the left side sunward during the waning phase.

ECONOMIST: Letters

The Economist can take solace that the original picture showing the waxing phase on the left side of the moon in Rio was indeed correct.

ECONOMIST: Letters