Iâve come up with fewer reasons for giving a child a cell phone earlier, but at least two of them are enough to offset a multitude of others. Keeping tabs on them. As each year passes in a childâs life they venture farther from home and for longer periods of time.
Like the inner planets, the outer planets have similar characteristics to one another. The outer planets are so much larger than the inner planets that they make up 99 percent of the mass of the celestial bodies that orbit the Sun. Although mainly composed of gas, the outer planets also have other ingredients.
1 Hence, terrestrial planets (Mercury, Venus, Earth, and Mars) are dense small worlds composed mostly from 2% of heavier elements contained in solar nebula. 2  Formation of jovian planets: 3  In the outer solar nebula, planetesimals formed from ice flakes in addition to rocky and metal flakes.