what are called terrestrial planets

Terrestrial planets are rocky planets that are composed primarily of silicate rocks or metals. They are called terrestrial because they have a compact, rocky surface like Earths terra firma. Terrestrial planets also have a molten heavy-metal core, few moons, and topological features such as valleys, volcanoes, and craters. In our solar system, there are four terrestrial planets: Mercury, Venus, Earth, and Mars. Earths Moon, as well as Jupiters moons Io and sometimes Europa, may also be considered terrestrial planets under the geophysical definition. Terrestrial planets are generally studied by geologists, astronomers, and geophysicists.