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%
Stability of the Solar System becoming significantly more—or less—elliptical. In calculation, the unknowns include asteroids, the solar quadrupole moment, mass loss from the Sun through radiation and solar wind, drag of solar wind on planetary magnetospheres, galactic tidal forces, and effects from passing stars. Furthermore, the equations of motion describe a process that is inherently serial, so there is little to be gained from using massively parallel computers. The Neptune–Pluto system lies in a 3:2 orbital resonance. C.J. Cohen and E.C. Hubbard at the Naval Surface Warfare Center Dahlgren Division discovered this in 1965. Although the resonance itself will remain stable in the short term,