Terraform what? The average temperature up there is about -30 celcius. That’s the average, who wants to live in that?
In the case of Mars, terraforming probably begins by generating enormous amounts of perfluorocarbons. They are extremely simple but potent “super” greenhouse gases that can be manufactured directly from the Martian regolith. They also have an exceedingly long lifespan.
“There are many positive qualities to PFCs. They are 100% environmentally safe, since they are chlorine-free and do not contain any toxins. Also, PFCs are easy to make. They can be produced using simple molecules of carbon, sulfur, and fluorine which are all abundant on Mars.
“if Mars’s atmosphere contained just a few parts per million of the super-greenhouse gases, the average temperature at the planet’s surface would rise from -60 to -40 degrees Celsius (-76 to -40 degrees Fahrenheit). This warming could be enough to trigger the release of carbon dioxide from the polar caps and soil into the atmosphere. Carbon dioxide would then augment the greenhouse effect even further, driving the release of more carbon dioxide and water vapor into the atmosphere. Such positive feedback would be sufficient to create a thick, warm atmosphere—the carbon dioxide Mars.”
I agree. The environment is far from known at this, that human life might eventually be sustainable is optimistic, and at what cost will it take to make it profitable.
I don’t know why NASA doesn’t pursue robotic missions until more information can be obtained. Why risk human life when machines can gather the information needed to make those decisions.