From Earth to Mars: The Quest for Extraterrestrial Habitation

“And after the Earth dies, some 5 billion years from now, after it’s burned to a crisp, or even swallowed by the Sun, there will be other worlds and stars and galaxies coming into being –and they will know nothing of a place once called Earth.”
Carl Sagan

On the morning of April 12, 1961, a woman and a young girl were walking to school in Saratov Oblast, Russia, when they saw a bright figure descending from the clouds. At first, they thought it was an angel. However, they noticed, on a closer look, that it was a man in the flesh. When that man landed on the ground and started running towards them, they backed away in fear. ‘I am a friend, comrades, a friend!’ shouted the man in the orange suit as he approached them. ‘Can it be that you have come from outer space?’ asked the flabbergasted woman. ‘As a matter of fact, I have!’ replied Yuri Gagarin.

If back then, someone had told that woman that, after 60 years, we would be preparing to send human missions to Mars, she would have laughed and called them insane. But were all great ideas that changed the course of history not considered insane at first?

The re-entry capsule of Vostok 1 after landing southwest of Engels in the Saratov Region. *Image courtesy: ESA*

Hunt for a Habitable Planet

Humans have been scouring space in a quest to understand the prospects of human survival and the evidence of extraterrestrial life on other planets for a long time. Ground-breaking space missions like Voyager 1, Kepler, and Cassini-Huygens have revolutionized the way astronomers look at our universe and have opened new fields in planetary science exploration.

As of July 2020, NASA’s prolific planet-hunting missions, Kepler and TESS, have discovered more than 4000 confirmed planets in our neighbouring solar-systems. Out of these, about 30 are Earth-sized exoplanets that orbit in their parent stars’ habitable zone – a region around the star where liquid water may exist on the planet’s surface. However, many astrophysicists and biologists believe that mankind might not have to venture very far into space to find a thriving habitat, for there is a potentially Earth-like planet much closer to home: Mars.

An artist’s depiction of Kepler Planet 1649c. Image courtesy: NASA

A mosaic composed of 102 images of Mars captured by the Viking Orbiter. Image courtesy: NASA

The Red Planet

Named after the Roman God of War, our cold and dusty neighbour Mars is about half the size of Earth. The surface area, however, is the same. It takes about eight months to reach Mars from Earth. A day on Mars is 24.6 hours long and a year lasts for 687 Earth days. The gravity on Mars is much lower — about 38 percent of Earth’s gravity. Though Mars is a dry, rusty planet today, evidence suggests that billions of years ago, before it underwent a cataclysmic climate change, Mars had a surface just like Earth.

Mars was the first planet in the Solar System that was explored for life-supporting conditions. In fact, more missions have been sent to Mars than to any other planet. Extensive data collected from several orbiters, landers, and rovers like Curiosity, MAVEN, and Mars Reconnaissance Orbiter proves that the Red Planet is the terrestrial planet that resembles Earth the most and thus, has the potential to be mankind’s next home.

**An artist’s impression of Mars four billion years ago. Image Courtesy: European Southern Observatory**

The Ingredients of Life and the Recipe of Mars’ Habitation

Liquid water is the first thing we search for on a potentially habitable planet because its presence is critical, not only for humans but for all living beings. Mars does have water and plenty of it but most of it is frozen, either on the polar caps or buried beneath the soil. In fact, there is so much water on Mars that if we only melted its polar ice caps, 30% of the planet would be submerged. But melting that ice would take years and a lot of equipment.

Images of the Martian North and South Polar Caps captured by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) on March 13, 1999, and April 17, 2000, respectively. Image Courtesy: NASA

Images by NASA’s Phoenix Lander on June 15 and June 19, 2008, respectively, showing the sublimation of ice in the Dodo-Goldilocks trench. *Image Courtesy: NASA*

So how does one extract water from Mars right away? Luckily, water also exists in small quantities as vapours in the Martian atmosphere. Data gathered from Viking Orbiter’s MAWD— Mars Atmospheric Water Detector — shows that the atmosphere of Mars is almost always 100% humid at night. In 1998, students from the University of Washington developed a system called WAVAR for producing water from the Martian atmosphere. It is a low-tech dehumidifier that uses the process of adsorption and condensation to extract water vapour from the atmosphere and turn it into liquid water. WAVAR has been successfully tested in Mars-like conditions on Earth, attaining proof of concept. However, as of yet, there has been no funding by NASA for further developments.

Layout of WAVAR for producing water from the Martian atmosphere
*Image courtesy: University of Washington Libraries*

Next comes oxygen. The Martian atmosphere comprises of 96% carbon dioxide and only 0.13% oxygen. Breathing in this air will be fatal for humans. We cannot take oxygen tanks from Earth so how do we produce oxygen on Mars? Michael Hecht, a professor at MIT, has developed a device called Mars Oxygen ISRU Experiment (MOXIE) which functions like a tree. It is a reverse fuel-cell which can suck in the CO2 from the Martian atmosphere, compress it and then convert it to O2. NASA’s Perseverance rover mission, which will reach Mars in February 2021, is carrying a sample model of MOXIE to be tested in Martian atmosphere. Findings of this mission will set the route for future human expeditions to Mars.

Subsystems on MOXIE. *Image Courtesy: MIT News*

Finally, we need an energy source. Mars receives energy from the Sun. However, because of its thin atmosphere and lack of a magnetic field, this energy is accompanied by constant bombardment of radiation and cosmic rays. So, how do we protect ourselves from this deadly radiation? Amy Ross, an advanced spacesuit designer, has created spacesuit samples that will be sent to Mars along with Perseverance Rover to see how they fare on its surface.

Amy Ross, advanced spacesuit designer, with the spacesuit prototype Z-2. *Image Courtesy: NASA*

Could Mars be Our Second Home?

MOXIE, WAVAR, and advanced spacesuits will undoubtedly aid short-term human exploration missions on the Red Planet. However, if we plan to stay there, we need long-term solutions to these challenges. To colonize Mars, we need to make it more like our home planet i.e. we have to completely re-engineer it.

Artist Daein Ballard’s depiction of the process of terraforming Mars. Image Courtesy: Wikimedia

Terraforming Mars will possibly take decades. However, from launching the first artificial satellite into the Earth’s orbit in 1957 to landing a probe on the Comet 67P in 2014, we have come a long way in our quest to find a second home in a very short period of time. NASA is currently preparing to send a human mission to Mars by the early 2030s while Elon Musk plans to land a man there by 2025. So, will we transcend and become the first spacefaring species or fade into oblivion in a million years? Will mankind eventually perish along with Earth or will it find a second home and survive? What does the future hold for our species? It remains to be seen.

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Shumaim Rashid Member since 2020-09-03

Shumaim is an A Levels student, currently taking a gap year. She enjoys trying to find constellations in the sky while listening to Lana Del Rey. Literature, astronomy and anime are some of the things that interest her. She believes that humans are destined to reach the stars and beyond.