Why jovian planets bigger

Once planets have such a mass they will grow considerably, collecting gases from the surrounding disk, while their smaller cousins will tend to stay smaller. Points L1, L2 and L3 are unstable, but points L4 and L5 - which form an equilateral triangle with the star and the planet are stable. Why are the Jovian planets so much larger than the terrestrial planets?

Astrophysics Universe Formation Planet Composition. George C. May 28, See explanation Explanation: Think of planets forming from the protoplanetary disk around a star. The answer lies in where these objects formed in relation to the parent star, our Sun. After the solar nebula collapsed to form our Sun, a disk of material formed around the new star.

The temperature across this protoplanetary disk was not uniform. Since different materials condense at different temperatures, our solar system formed different types of planets.

The frost line marked an important dividing point in the solar nebula. All terrestrial planets formed inside the frost line and were closer to the Sun, where temperatures are high. In this region, hydrogen compounds, such as water and methane remains gaseous. Thus, the terrestrial planets accreted from planetesimals made of rocks and metals, they ended up too small to capture significant amounts of the abundant hydrogen and helium gas in the solar nebula.

Any moon in a planet near the Sun will have an unstable orbit and later may be captured by the Sun. This ejected material then merged and formed the Moon. Mercury and Venus are moonless. One theory said both planets should have at least one small satellite. All four jovian planets have rings composed of countless small pieces of rock and ice, each orbiting its planet like a tiny moon. Why do they have so many moons?

The jovian planets formed outside the frost line, farther from the Sun, where the temperature is much colder. In this region, ices and rocks were plentiful. Rock and metal are still present in the outer solar system, but both are outnumbered and outweighed by the hydrogen compounds. Thus, the planetesimals that formed in the outer solar system are composed primarily of hydrogen compounds with traces of rock and metal.

The cores accreted rapidly into large clumps of ice and rock. Eventually, they got so large that they captured a large amount of hydrogen and other gasses from the surrounding nebula with their enormous gravity. All jovian planets are massive and they do have stronger gravitational force. Thus, they can capture all leftover material and had their own protoplanetary disk of gas, dust and ice surrounding them. These planets contain different materials within their cores, formed from various elements.

Their inner cores mostly contain ice and solid particles. The surrounding layers, however, form from gases. They are derived primarily from hydrogen and helium, along with compounds containing these elements. Unlike the organic materials that form the terrestrial planets, helium and hydrogen never condense in the atmospheres of the Jovian planets.

Instead, the gases accumulate, letting the surface sizes of outer planets expand infinitely.