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Is it possible that one day we could make Mars an Earth-like planet? — Tyla, 16, Mississippi
When I was in middle school, my biology teacher showed our class the science fiction movie Star Trek III: The Search for Spock.
The plot drew me in, with its depiction of the “Genesis Project” – a new technology that transformed a dead alien world into one teeming with life.
After seeing the movie, my professor asked us to write an essay on this technology. Was it realistic? Was it ethical? And to channel our inner Spock: Was it logical? This assignment had a huge impact on me.
Today, I am an engineer and professor, developing technologies to extend human presence beyond Earth.
For example, I work on advanced propulsion systems to fly spacecraft beyond Earth orbit. I help develop lunar construction technologies to support NASA’s goal of a long-term human presence on the Moon. And I was part of a team that demonstrated how to 3D print habitats on Mars.
It will take a lot of time, energy and imagination to ensure the survival of populations beyond Earth. But engineers and scientists have begun to address the many challenges.
A partial checklist: food, water, shelter, air
After the Moon, the next logical place for humans to live beyond Earth is Mars.
But is it possible to terraform Mars, that is, transform it so that it resembles Earth and supports life? Or is this just a science fiction dream?
To live on Mars, humans will need liquid water, food, shelter, and an atmosphere that contains enough oxygen to breathe and is thick enough to trap heat and shield against radiation from the Sun.
But the Martian atmosphere is almost entirely carbon dioxide, with virtually no oxygen. It is also very thin: only about 1% as dense as Earth’s.
The less dense an atmosphere is, the less heat it can trap. The Earth’s atmosphere is thick enough to trap enough heat to support life through something called the greenhouse effect.
But on Mars, the atmosphere is so thin that the nighttime temperature regularly drops to -101 degrees Celsius.
So what’s the best way to give Mars an atmosphere?
Although Mars doesn’t currently have any active volcanoes—at least that we know of—scientists could trigger volcanic eruptions with nuclear explosions. Gases trapped deep within a volcano would be released and then drift into the atmosphere. But this is a bit far-fetched, because the explosions would also introduce deadly radioactive material into the air.
A better idea: redirect water-rich comets and asteroids to crash into Mars. This would also release gases from beneath the planet’s surface into the atmosphere, while releasing the water in the comets. NASA has already shown that redirecting asteroids is possible, but it takes relatively large asteroids and a lot of them to make a difference.
Making Mars Comfortable
There are many ways to warm the planet. For example, giant mirrors, built in space and placed in orbit around Mars, could reflect sunlight back to the surface and warm it.
A recent study suggested that Mars colonists could spread aerogel, an ultralight solid material, on the ground. The aerogel would act as an insulator and trap heat. This could be done anywhere on Mars, including on the polar ice caps, where the aerogel could melt existing ice to produce liquid water.
To grow food, you need soil. On Earth, soil is made up of five elements: minerals, organic matter, living organisms, gases, and water.
But Mars is covered in a layer of loose, dust-like material called regolith. Think of it like Martian sand. Regolith contains few nutrients, not enough for healthy plant growth, and it contains harmful chemicals called perchlorates, which are used on Earth in fireworks and explosives.
Cleaning up the regolith and turning it into something viable won’t be easy. This alien soil needs Martian fertilizer, perhaps made by adding extremophiles – hardy microbes imported from Earth that can survive even the harshest conditions. Genetically modified organisms are also a possibility.
Through photosynthesis, these organisms would begin to convert carbon dioxide into oxygen. Over time, as Mars became more suitable for life for terrestrial organisms, colonists could introduce more complex plants and even animals.
Providing oxygen, water, and food in the right proportions is an extremely complex task. On Earth, scientists have attempted to simulate this phenomenon in Biosphere 2, a closed ecosystem that includes ocean, tropical, and desert habitats. Although all of Biosphere 2’s environments are controlled, even there, scientists struggle to find the right balance. Mother Nature really knows what she’s doing.
A house on Mars
The buildings could be 3D printed. First, they would need to be pressurized and protected until Mars reaches Earth-like temperatures and air. NASA’s Moon-to-Mars Planetary Autonomous Construction Technologies program is studying how to do this.
There are many other challenges to overcome. For example, unlike Earth, Mars does not have a magnetosphere, which protects the planet from solar wind and cosmic radiation. Without a magnetic field, too much radiation passes through the planet for living things to stay healthy. There are ways to create a magnetic field, but so far the science remains highly speculative.
In fact, all of the technologies I have described are far beyond current capabilities at the scale needed to terraform Mars. Their development would require enormous amounts of research and money, probably far more than is possible in the short term. Although the Genesis device of Star Trek III A planet could be terraformed in minutes, whereas terraforming Mars would take centuries or even millennia.
There are many ethical questions to be answered before people embark on the task of transforming Mars into another Earth. Is it right to make such radical and permanent changes to another planet?
If all this disappoints you, don’t be. Scientists are innovating to terraform Mars, but we’ll also use it to improve life on Earth. Remember the technology we’re developing to 3D print habitats on Mars? Right now, I’m part of a group of scientists and engineers using that same technology to print homes here on Earth, which will help solve the global housing shortage.
Sven Bilén is a professor of engineering design, electrical engineering, and aerospace engineering at Penn State University. This article is republished from The Conversation under a Creative Commons license. Read the original article. The views and opinions expressed in this commentary are solely those of the author.