Thirsty in Mars or Thirsty for Mars ?

Thinking about how fast we humans are jumping on different planets in order to colonize them, we often leave behind some big questions unanswered. Most of these only arise when we actually go there. For any type of survival there always are some thumb rules to begin with. Amongst things like Oxygen for breathing and Food for consumption, one other big concern is Water for practically most common little things associated with it and of course for drinking.

Mars Viking Rovers

The Famous Path-Finder

Recently humans have been trying to reach on the Big Red Planet named after a Greek God, Mars. Missions like 1997 Mars Pathfinder rover , 2008 The Phoenix Mars Lander , The whole NASA's Mariner series along with many more have either successfully or partially been sent to Mars (“Mars Exploration Past Missions”). Till date we have only sent satellites, rovers and robots on the atmosphere and land of Mars. Their mission mainly used to be to collect data to gather soil and rocks and to get nice images for us to drool on. Mars if seen is a big sandy dune-like desert. 

What is Mars' atmosphere made of?

Mars as captured by NASA's rovers

Although the atmosphere of Mars used to be thick enough for water to flow on the surface, such water is now sparse or non-existent. The climate of Mars is hundreds of times thinner than Earths. It is basically 95% carbon dioxide. Here is what a Nasa Fact Sheet (Sharp) has to tell us about its breakdown:

• Carbon dioxide: 95.32 percent

• Nitrogen: 2.7 percent

• Argon: 1.6 percent

• Oxygen: 0.13 percent

• Carbon monoxide: 0.08 percent

• Also, minor amounts of: water, nitrogen oxide, neon, hydrogen-deuterium-oxygen, krypton and xenon

Mars had a thick enough atmosphere early in its history (especially in times older than 3.5 billion years ago) for water to run on its surface. Large river plains and putative ocean limits may be seen in orbital images, and numerous Mars rovers have discovered evidence of water-soaked rocks on the surface (such as hematite or clay). The Martian atmosphere, on the other hand, thinned for reasons that are yet unknown. Another talked theory is that Mars light gravity combined with the lack of global magnetic field caused the atmosphere exposed to the solar wind. Over a course of millions of years the constant sun's pressure stripped the lighter molecules from the atmosphere, gradually thinning it out.

Water on Mars is not less of a mystery on its own. NASA's phoenix mission found out that Mars possesses Large amounts of Ice . It also found signs that the planet's arctic plains were covered with a film of liquid water in the last few million years. The only place where water ice is visible at the surface is at the north polar ice cap. Abundant water ice is also present beneath the permanent carbon dioxide ice cap at the Martian south pole and in the shallow subsurface at more temperate conditions. More than 5 million km³ of ice have been detected at or near the surface of Mars, enough to cover the whole planet to a depth of 35 meters. 

Sadly enough, No large standing bodies of liquid water exist on the planet's surface, because the atmospheric pressure there averages just 610 pascal . More than a million years ago Mars may have had a thicker atmosphere and higher surface temperature allowing liquid to flow on its surface.

All aforementioned data is according to modern day science and facts, however in movies like The Martian, some other ways of obtaining water on mars are discussed.

How Mars was shown in " The Martian "

Interesting to note that he did not only need water to survive on its own, but also to cultivate and grow food there. In the film Matt Damon plays Mark Watney, one of the first astronauts to walk on Mars. Damon’s character produces water by burning leftover rocket fuel and extracts the hydrogen from the resulting chemical reaction. 

the explosion scene

Hydrazine has been used as rocket fuel for Mars landers for a long time. Viking, Phoenix, and, Curiosity, all used hydrazine powered rockets to land. It's a fairly low power, low efficiency fuel for a rocket but it's attractive because it's a monopropellant -- meaning you don't need an oxidizer to burn it.

For a rocket engine, hydrazine (N2H4) is passed through a catalyst which causes it to decompose into ammonia, nitrogen gas, and hydrogen gas

N2H4 → N2 + 2 H2

In the movie The Martian, Mark Watney used that same reaction to produce the hydrogen gas and then, in combination with the oxygen in the hab, he burned the hydrogen and made water.

2H2 + O2→ 2 H2O

He didn't actually capture or store the water - he just let it accumulate and be absorbed directly into his farm soil for the potatoes.

Damon while checking for his planted potatoes

However In reality that wouldn't be quite easy

First, hydrazine is incredibly toxic. Just wearing a mask, like the movie showed, would still leave your skin exposed and would be incredibly dangerous. 

Second, decomposing the hydrazine into nitrogen and hydrogen is highly exothermic. It gives off a lot of heat. A lot of heat.

800 degrees Celsius in a matter of milliseconds.

Never mind an explosion - Mark Watney would have been cooked long before that...​And with that heat comes a massive expansion of the gases. It's very hot and very fast -- which is why it is so good for a rocket engine.

Which is why it so difficult -- and dangerous -- to use this process for making clean water on Mars.​

Finally, if you were able to contain​ the gases and the heat, you would still be limited by the amount of water that could be produced. You would need a constant supply of hydrazine from Earth to support a settlement of thousands.

It's just not feasible.​

In conclusion, many hypothesis are there but practically none have been performed till date.

Lets hope in the near future we see successful Mars Mission which are able to make water on Mars.

By Moid Khan

2021

References:

1) “Mars Exploration Past Missions.” NASA, 2011, www.nasa.gov/mission_pages/mars/missions/index-past.html.

‌2)Sharp, Tim. “Mars’ Atmosphere: Composition, Climate & Weather.” Space.com, Space, 12 Sept. 2017, www.space.com/16903-mars-atmosphere-climate-weather.html.

‌3)“Behind the Science of the Martian | Astronomy Magazine.” Astronomy.com, 2012, www.astronomy.com/bonus/martian.

4)Wikipedia Contributors. “Water on Mars.” Wikipedia, Wikimedia Foundation, 14 Nov. 2021, en.wikipedia.org/wiki/Water_on_Mars#Present_water

5)All pictures taken from www.google.com

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