Why do the outer giant planets have massive gaseous atmospheres of hydrogen and helium while the inner planets do not?
A) These gases were more abundant in the outer regions of the accretion disk where the outer planets formed.
B) The outer planets grew massive quickly enough to gravitationally hold on to these gases before the solar wind dispersed the accretion disk.
C) The inner planets were too close to the Sun, and the solar wind blew away their original gaseous atmospheres.
D) Frequent early collisions by comets with the inner planets caused most of their original atmospheres to dissipate.
E) Temperatures were too high in the region of the Solar System that contains the inner planets.

Question

Quizplus · Accepted Answer

The outer planets grew massive quickly enough to gravitationally hold on to the hydrogen and helium gases before the solar wind dispersed the accretion disk. The solar wind would have blown away any such gases that may have been present near the inner planets during the formation of the Solar System.

Why Do the Outer Giant Planets Have Massive Gaseous Atmospheres