Circling back to my note on solar wind and the Martian atmosphere.
In the note, I described how the solar wind interacts with the ionosphere of Mars to create an induced magnetosphere. Recent data from ESA’s Mars Express mission suggests that this induced magnetosphere actually protects the Martian atmosphere from the ion loss expected to be caused by that same solar wind. Thus, the long held idea that the solar wind blew away Mars’ atmosphere is now in question.
The article below outlines an alternative hypothesis. Rather than losing atmosphere to the solar wind, maybe Mars can’t hold onto one because its gravity is just too weak.
phys.org