This is the last part of our four part 'Mars May' series where we discuss the missions and technologies enabling Mars exploration.Mars is a tantalizing goal for the next step in human exploration. However, the fourth, rocky planet from the Sun is a harsh world to live on. Terraforming offers the possibility of making Mars a new home for humans, but the challenge is immense. We dive into some of the key aspects of Mars colonization and terraforming today on SPEXcast. You can check out additional links and references at https://blog.spexcast.com/terraforming-mars-challenges-and-misconceptions .