An inner planet is observed (through a telescope) to have a gibbous shape whenever it is close to:

Question

Quizplus · Accepted Answer

When an inner planet is close to superior conjunction (being on the opposite side of the Sun from Earth), it appears to be in a gibbous phase, meaning that it appears more than half but not fully illuminated. This is because the illuminated part of the planet that is facing the Sun is not fully visible from Earth due to the planet's position in relation to the Sun and Earth.

An Inner Planet Is Observed (Through a Telescope) to Have