Which among the following planets is smaller in size than the Earth?

The Solar System consists of eight planets categorized into small terrestrial planets and large gas/ice giants. Earth is the largest of the terrestrial planets with a diameter of approximately 12,756 km [t1, t4]. Venus is frequently referred to as 'Earth's twin' due to its similar mass and density, but it is slightly smaller in size with a diameter of about 12,104 km [c4, t1, t5]. In contrast, the outer planets are significantly larger than Earth. Neptune has a diameter of approximately 49,528 km, Uranus measures about 51,118 km, and Saturn is a massive gas giant with a diameter of roughly 120,536 km [t1, t5]. Therefore, among the given options, only Venus is smaller than Earth. Mercury and Mars are the only other major planets smaller than Earth, while Jupiter, Saturn, Uranus, and Neptune are all substantially larger [c1, t2, t3].

Sources

1. [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 13: Our Home: Earth, a Unique Life Sustaining Planet > 13.2 What Do the Planets of Our Solar System Look Like? > p. 213
2. [2] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 2: The Earth's Crust > The Solar System > p. 2