The idea of terraforming Mars has captured millions of people's imagination, especially in recent times.
Turning Mars into a potentially habitable planet is, without a doubt, possible. But the terraforming process is far more complicated than most would assume.
There are a number of obstacles involved, with each one having its own set of challenges. The biggest problem is the fact that Mars no longer has a magnetic field to protect it from high levels of cosmic radiation and solar winds. Although these levels are relatively low, it would prevent life from thriving naturally, regardless if we solve the atmosphere problem.
However, there is a possible solution that, at this point, is the most convincing. The magnetic shield concept involves placing an artificial magnetic field between Mars and the Sun at the exact point where the gravitational pull between the two bodies cancels each other out at a state of perfect equilibrium. This point is called the Lagrange Point 1. The Magnetic shield will then deflect any radiation and solar wind from penetrating the surface of Mars.
This would then allow Mars to slowly regenerate a greenhouse effect, thus melting the polar ice, creating oceans and atmosphere, and eliminating exposure to harmful cosmic radiation. This concept alone will likely work, but according to the research involved, this process may take hundreds, if not, thousands of years.
To speed this process up, more greenhouse gasses need to be dumped into Mars' atmosphere, this will also speed up the process in order to get an atmospheric pressure similar to that of the Earth.
However, it will be quite some time before the atmosphere gets to a point where you could safely walk on Mars without assisted breathable oxygen. In order for this to happen, microbes and mosses that we plant there need sufficient time to convert carbon dioxide into oxygen.
As for the technical hurdle of an ozone layer, ozone will need to be mass-produced in a permanent factory on the surface of Mars and then released into the atmosphere.
When we eventually get Mars to a habitable environment, we would have to adjust to the natural characteristics of the red planet. For starters, Mars' gravity pull is only 30% to that of the Earth, secondly, the days will be longer, the years will be almost double the amounts of days for a complete orbit around the Sun, and the seasons will be sufficiently longer, which will cause much hotter summers and long-lasting colder winters.
Take a look at the video below by the YouTube channel, Futurology, on How To Terraform Mars...