I think we should be working out how to modify/terraform the atmosphere of Venus so we can live on the surface. At the rate we're going, we're going to need that tech on Earth. So once it's perfected here, we can then get our sister planet back to functional too
Venus needs a lot of work that Mars doesn’t. I think the main problem is the rotation period. The amount of energy required to speed up the day of planet is unthinkable.
