which planet is smaller than earth
Pluto is not a planet so that would be Mercury is 13.72% smaller. Venus is 0.23% smaller. Mars is 9.42% smaller. So that means 3 planets are smaller than Earth. 48 people found this useful.
The planets of the Solar System can be divided into categories based on their composition: 1  Terrestrials: Planets that are similar to Earth, with bodies largely composed of rock: Mercury, Venus, Earth and Mars. At 0.055 Earth masses, Mercury is the smallest terrestrial planet (and smallest planet) in the Solar System. Earth is the largest terrestrial planet.