brightest planet

The planet that gets brightest as viewed from Earth is Venus. Its maximum magnitude is -4.4. Venus is the planet that approaches nearest to Earth, but it is also the most effective at reflecting sunlight because it is covered by cloud. Venus's cloud tops reflect 76% of the sunlight falling on them. When Venus is at its brightest, it is at crescent phase. Because Venus's orbit is nearer the Sun than Earth's, the disk of Venus is only fully illuminated - or nearly so - when Venus is on the opposite side of the Sun from Earth, where it is at its greatest distance and smallest apparent diameter. When Venus is on the same side of the Sun as Earth, only a crescent of its sunlit side is visible from Earth, but that crescent has a much greater apparent area on the sky than 'full' Venus does at its much greater distance.