After Earth, if we want to live in some other planet, Mars seems to be the next best choice for that. But, survival on Mars is impossible right now. So, if it becomes completely necessary to recolonize in the future, can we survive on Mars anyway? Well, let me explain that in detail.
The Survival Challenges On Mars
If we send a group of people to Mars right now, there is absolutely no way for them to build a colony there. The technology we have right now cannot bring them back to earth either so, it'll end up being a one-way journey anyway. The geographical aspect of Mars is completely different than Earth. There is no edible water source (at least none of that has been discovered yet), there is no atmosphere and you cannot grow plants on it's surface. Let's look at two of the biggest issues that we'll face on Mars.
Gravity: The Gravitational Force is a huge problem on Mars. The gravity of Mars is weaker and not enough to hold onto Earths atmosphere. So, given that Mars doesn't have a atmosphere where humans can survive, we'll need to generate the Earths atmosphere artificially. But, even if we manage to generate earths atmosphere artificially, it'll get out of the gravitational attraction of Mars & get distributed in space. So either we have to keep generating forever or we have to find a way shield the colonies so, the gasses cannot escape. By the way, Mars also doesn't have the magnetic field like Earth.
UV Rays: Now, let's say we somehow manage to sustain our atmosphere on Mars. But, we probably cannot create an Ozone layer right? So, that'd mean direct UV rays from the Sun hitting the surface which will kill you if you're not in a space suit. But, that's not the biggest problem here. The problem is drinking water or just water in general. Unfiltered & direct UV Rays will literally break the molecules of H2O, separating Hydrogen and Oxygen. So, that means it'll be really hard to sustain proper water supply on Mars. So, whatever we're shielding the colonies with to sustain the atmosphere, also needs to shield it from the direct UV Rays coming from the sun.
So, as many issues we talked about does't really close the list of problems. What will we eat on Mars? Will we be in spacesuits all the time or whenever we get outside? Where will the required Oxygen come from? And the list keeps going on.
Does That Mean We Won't Be Able To Survive On Mars?
If you're talking about living in Mars right now then no. But, we are a civilization that has achieved a huge number of goals that seemed impossible at first. So, I'm sure that our scientists & engineers will figure out a way to overcome all the survival and transportation obstructions on Mars. When that happens & if the day comes when Earth will be inhabitable, sure, we'll live on Mars and you know, survive as well.