“Birth of the Earth,” page 37, talks about how the atmosphere of a planet starts with the light atoms of the protoplanet that are: a) above the surface of the rocky planet and b) under the ice layer. It is further explained on page 37 that due to the lack of a magnetosphere on both Venus and Mar, the ice layer has been scrubbed away and the atmosphere eroded. The image above from the Solar Dynamics Observatory (a project of NASA) shows an X2 flare and a coronal mass ejection from the Sun which caused energetic particles to be pushed out across the solar system—a stronger, more energetic contribution to the every-day common solar winds.
The week of November 4, 2015, NASA released information to verify that they see the atmosphere of Mars being striped away by the solar winds. Here is a video from Space.com regarding Mars Atmosphere Being ‘Stripped’ By Solar Wind.
From the New York Times article on this matter:
But new readings from NASA’s Mars Atmosphere and Volatile Evolution mission — Maven, for short — show that when Mars is hit by a solar storm, the ferocious bombardment of particles from the sun strips away the upper atmosphere much more quickly.
…The air disappears in mainly two ways. Sometimes an electron is knocked off an atom in the upper atmosphere, and then the charged atom is accelerated away by the electric and magnetic fields of the solar wind. Particles of air can also be knocked into space through collisions with incoming solar wind particles, like billiard balls.
It is nice to have this rigorous confirmation with details regarding the mechanisms for how the atmosphere-striping behavior happens at the atomic level.