Geology of solar terrestrial planets billions of years ago in the cores of massive stars. These elements constituted only 0.6% of the material in the solar nebula. That is why the terrestrial planets could not grow very large and could not exert large pull on hydrogen and helium gas. Also, the faster collisions among particles close to the Sun were more destructive on average. Even if the terrestrial planets had had hydrogen and helium, the Sun would have heated the gases and caused them to escape. Hence, solar terrestrial planets such as Mercury, Venus, Earth, and Mars are dense small worlds composed mostly from 2%
Formation and evolution of the Solar System from the asteroid belt or excited their orbital inclinations and eccentricities. Some of those massive embryos too were ejected by Jupiter, while others may have migrated to the inner Solar System and played a role in the final accretion of the terrestrial planets. During this primary depletion period, the effects of the giant planets and planetary embryos left the asteroid belt with a total mass equivalent to less than 1% that of the Earth, composed mainly of small planetesimals. This is still 10–20 times more than the current mass in the main belt, which is now about . A secondary