What are the inner planets?

In our Solar System, astronomers often divide the planets into two groups — the inner planets and the outer planets. The inner planets are closer to the Sun and are smaller and rockier. The outer planets are further away, larger and made up mostly of gas. read more

In the inner Solar System, we find the “Inner Planets” – Mercury, Venus, Earth, and Mars – which are so named because they orbit closest to the Sun. In addition to their proximity, these planets have a number of key differences that set them apart from planets elsewhere in the Solar System. read more

The inner Solar System is the region comprising the terrestrial planets and the asteroid belt. Composed mainly of silicates and metals, the objects of the inner Solar System are relatively close to the Sun; the radius of this entire region is less than the distance between the orbits of Jupiter and Saturn. read more

The inner four planets are called terrestrial planets. That means that they are like the earth in some ways. The terrestrial planets Mercury, Venus, Earth, Mars, and the earth's moon have similar compositions and densities. read more

The four inner planets of the solar system — those closest to the sun — are terrestrial planets having Earth-like features. The four inner planets of the solar system — those closest to the sun — are terrestrial planets having Earth-like features. read more