THE ROCKY INNER PLANETS
The four innermost planets in the Solar System
(Mercury, Venus, Earth, and Mars)
are sometimes called the "terrestrial" planets because
of their proximity to Earth and their similarity as
compact solid bodies with rocky surfaces.
What is a terrestrial planet?
A terrestrial planet, telluric planet or rocky planet is a planet
that is composed primarily of silicate rocks or metals.
Terrestrial planets also have a molten heavy metal core,
few moons, and topological features such as valleys, volcanoes and craters.
l These are the terrestrial planets l
Why terrestial planets are rocky?
Heat from the Sun evaporated lightweight elements like
hydrogen and helium into interplanetary space.
Mostly rock and metal was left in this zone and clumped together to form the inner rocky planets.
How the inner planets were formed?
Collisions among the objects eventually caused the
number of protoplanets to decrease as the size of the accreted bodies grew.
