This is the second part of our series on mars. I've made this post easy for you so you won't have to read the earlier post, but just in case, here is the link to why we suffocate on mars... and possible solutions.
In the last post, we talked about the very thin atmosphere that mars has on it. We saw that it is currently lethal and it has to be changed if humans are ever planning to live there. Some of our questions were left unanswered. I'll try to advance further into our discussion about terraforming our new planet, and I'll try to answer our questions from the old post.
When Elon Musk was asked about the risks of the journey to mars, he kind of treated the question as if it was not a problem at all. And although space agencies are worried about it, there might just be a way out. Without protection from the radiation from sun, the risk of death by cancer increases to about 5%. This risk can be decreased a lot and we are working on it. What we worry about, is our bones being weakened by prolonged exposure to zero gravity. The journey will last anywhere between seven to ten months. We seriously need to find a solution to this problem. Although exercise helps a bit, it won't solve the problem completely.
Now about being on mars - All the time, our sun throws out charged, magnetized particles at high speeds, we call this the solar wind. The solar wind particles rip off a planet’s atmosphere by striking the molecules in there and shooting them into space. For a planet like earth, the magnetic field acts as a protective layer. But a planet like mars which lacks a powerful magnetic field loses the gas molecules that form its atmosphere. Currently, this rate is about 100 grams per second. And if we make some easy calculations, mars is currently losing 1000 grams or 1 kg of its atmosphere every 10 seconds. And it is also throwing out gases from its crust, hence maintaining a very low atmospheric pressure of about 0.6 kPa on its surface.
This is a huge loss to us. If we are to live there, we need that atmosphere to stay on mars and not be lost in space. This would make the planet more habitable. Let's see more about this.
Let's take the case of our earth. The gases in the atmosphere have some mass. This results in some force between these gases and our earth due to gravity. This force, per unit area of earth, gives us the atmospheric pressure. Simply put, more the amount of gases, more their mass, and hence, more the atmospheric pressure.
We are evolved for higher atmospheric pressures of about 100 kPa. Atmospheric pressure below 6.3 kPa (called the Armstrong limit) is lethal for us. Right now, on mars, it is 0.6 kPa. We won't last half a minute without a pressure suit protecting us.
As of now, we don't have a clear solution to this problem. We only have ideas that we can work on so we could eventually, in near future, solve this problem.
As 
These devices have two to three nuclear explosions in a single weapon, one explosion triggering the next. BUT in defense of the nuclear fusion process, the energy yield is much higher with lesser radioactive damage compared to the old nuclear fission process used in our nuclear power stations. That is relatively cleaner energy. I mean the process, not the bomb, which is a man-made disaster, awaiting a nod from leaders with questionable intentions. Do we still count as the smartest animals on earth?
Anyways, nuclear fusion process (two atoms join to make one atom) is much more powerful and yet a cleaner process compared to nuclear fission (one atom breaks into two). Power stations using nuclear fusion are on their way. Yes, I guess we thought of weapons first and power stations later. Anyways, these are the weapons Elon Musk has suggested for heating up the entire planet. Can you imagine their power?
Good news is that it would be up to the people living on mars to make the choice. These bombs would be used to create an atmosphere instead of destroying it, as would happen on earth. Byproducts of nuclear fusion last only a few months, and most of the radiation will be lost in space, but it is still very risky. It is first a nuclear fission explosion that triggers the second nuclear fusion explosion. Let's see the consequences.
Mars has ice on it, which is basically frozen water and carbon dioxide. When it is summer on mars, this carbon dioxide ice gets vaporized, and hence forms some atmosphere on mars, but as summer ends, temperature drops and the carbon dioxide is frozen to ice again. To avoid this, Elon Musk is suggesting warming the planet permanently. The thermonuclear bombs would act like two little suns on both sides of the planet. This would melt the CO2 ice as well as water ice. It would also increase the temperature of the planet by 4 ⁰C. And it would increase the atmospheric pressure on the planet's surface, hence making it more habitable... or so he says.
One possible disadvantage is that the poles have water in the form of ice as well. What if the water molecules break into hydrogen and oxygen molecules, and hydrogen being light, escapes the atmosphere of mars, this might happen more easily due to the solar wind. We'd only be left with oxygen. Good news is we might be able to breathe there. Or the carbon dioxide combines with water to give carbonic acid (H2CO3), which might turn out to be stable in mars' environment, since there is much less water already. No good news here. We could lose a lot of water, and air as well. And whatever water would be left might get contaminated by the radiation from the bombs.
Another solution is to give mars a protective magnetic shield. This is not possible anytime soon, but very possible in near future. Yes, the shield will always stay between the sun and mars. This also means mars and the shield will be orbiting the sun together. And also, we can always draw a straight line between sun, our shield, and mars. I’m stressing this to show that the planet will always be shielded. We call such an orbit the L1 orbit of the planet. But is it okay to rely on a shield to spend a lifetime on an otherwise harmful place? Not like we don’t do that on earth, but we are evolved for this environment since millions of years. We aren’t evolved for mars!
Most important fact I need to mention is, at lower pressures, water boils at lower temperatures. This I've explained very clearly for you in the last post. And as 
There are so many references, but I sorted out some for you. Feel free to check these out for more information.
- https://en.wikipedia.org/wiki/Terraforming_of_Mars
- http://www.swpc.noaa.gov/phenomena/earths-magnetosphere
- https://www.nasa.gov/centers/goddard/news/topstory/2005/mgs_plates.html
- http://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf
- https://www.forbes.com/sites/startswithabang/2017/07/15/ask-ethan-is-it-foolishness-to-dream-of-terraforming-mars/
- https://www.space.com/31044-mars-terraforming-nasa-maven-mission.html
- https://www.nasa.gov/feature/goddard/real-martians-how-to-protect-astronauts-from-space-radiation-on-mars
- https://www.nasa.gov/hrp/bodyinspace
- https://www.nasa.gov/sites/default/files/files/1_NAC_HEO_SMD_Committee_Mars_Radiation_Intro_2015April7_Final_TAGGED.pdf
- https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html
See you soon, take care.