Consider the following statements in case of terrestrial planets :

I. Mercury, Venus, Earth and Mars are terrestrial planets having low densities as compared to other planets.
II. They lie between the Sun and the belt of asteroids.
III. Their lower gravity can hold the escaping gases.

Which of the statements given above is/are correct?

Statement I is incorrect because terrestrial planets (Mercury, Venus, Earth, and Mars) have higher densities compared to Jovian planets (Jupiter, Saturn, Uranus, and Neptune), which are composed mostly of gases and ice. Statement II is correct as the terrestrial planets are the 'inner planets' located between the Sun and the asteroid belt. Statement III is incorrect because terrestrial planets are smaller and have lower gravity compared to Jovian planets. This lower gravity, combined with their proximity to the Sun and the intensity of solar winds, meant they could not hold onto the lighter escaping gases like hydrogen and helium. In contrast, the Jovian planets, being larger and further from the Sun, have higher gravity and could retain thick atmospheres of light gases.