We know that icecaps form on mars, that they are made of CO2, and that their size changes rather drastically from "winter" to "summer".

If the energy output from the sun changed enough to cause an ice age on Earth with glaciers kilometers thick, made of water ice, spreading south as far as the 49th parallel, then what might have been happening on Mars?

I would guess that changes in solar energy output would affect the entire solar system. Mars may have been totally socked in with glaciers made of CO2, flowing and carving out the landscape over centuries, especially as they receded.

Now I am wondering what might have happened to the other planets, Jupiter and its giant red spot... Saturn?