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

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

That phase will last about three months, as the Moon completes three rotations beneath the orbits of the two satellites.

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