Could We Terraform Mars?

We already have the technology to bring humans safely to Mars and set up small settlements - or at least could do within a generation. But those settlements will need to be cocooned - shielded against the deadly cold, intense radiation, and the fatal lack of atmospheric pressure. Surely if we want to thrive on Mars – to make it into our second home – these settlers, or their descendants, will need to be able open the airlocks, shed their spacesuits, and step out onto a survivable surface. We’ll need to terraform Mars, as our first step in terraforming the galaxy.