Giovanni Battista Zupi or Zupus (2 November 1589 – 26 August 1667) was an Italian astronomer, mathematician, and Jesuit priest.
In 1639, Giovanni was the first person to discover that the planet Mercury had orbital phases, like those of the Moon and Venus.
His observations demonstrated that the planet orbited around the Sun.
The crater Zupus on the Moon is named after him.
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