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 captivated me with its portrayal of the Genesis Project – a new technology that transforms a dead alien world into a world full of life.
After watching the movie, my teacher asked us to write an essay about 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.
Examples: I’m working on advanced propulsion systems to take spacecraft beyond Earth’s orbit. I’m helping to develop lunar building technologies to support NASA’s goal of long-term human habitation on the moon. And I was part of a team that demonstrated how to create habitats on Mars using 3D printing.
Providing supplies to people beyond Earth will require a great deal of time, energy and imagination, but engineers and scientists have begun to address the many challenges.
An incomplete checklist: food, water, shelter, air
After the Moon, Mars is the next logical place for humans outside of Earth.
But is it possible to terraform Mars – that is, to transform it into something more like Earth and support life – or is this just a fantasy from science fiction?
To live on Mars, humans need liquid water, food, shelter, and an atmosphere that provides enough oxygen to breathe and is thick enough to retain heat and protect against the sun’s radiation.
But Mars’ atmosphere consists almost entirely of carbon dioxide and contains practically no oxygen. And it is very thin – only about 1% as dense as Earth’s.
The thinner an atmosphere, the less heat it can store. The Earth’s atmosphere is thick enough to store enough heat to support life through what is known as the greenhouse effect.
On Mars, however, the atmosphere is so thin that the temperature regularly drops to -101 degrees Celsius (150 degrees Fahrenheit below zero) at night.
So what is the best way to give Mars an atmosphere?
Although there are currently no active volcanoes on Mars, as far as we know, scientists could trigger volcanic eruptions using nuclear explosions. The gases trapped deep within the volcano would be released and released into the atmosphere. But this plan is a little crazy, because the explosions would also release deadly radioactive material into the air.
A better idea: redirecting water-rich comets and asteroids so that they crash into Mars. This would also release gases from the planet’s subsurface into the atmosphere, while also releasing the water contained in the comets. NASA has already shown that it is possible to redirect asteroids – but you need relatively large asteroids and lots of them to make a difference.
Making Mars comfortable
There are numerous ways to warm the planet. For example, giant mirrors built in space and placed in orbit around Mars could reflect sunlight onto the surface, warming it.
A recent study suggested that Mars colonists could spread aerogel, an ultralight solid material, on the ground. The aerogel would act as insulation and retain heat. This could happen anywhere on Mars, including the polar ice caps, where the aerogel could melt existing ice and create liquid water.
To grow food, you need soil. On Earth, soil is made up of five components: minerals, organic matter, living organisms, gases and water.
But Mars is covered by a layer of loose, dust-like material called regolith. You can think of it like Martian sand. The regolith contains few nutrients, not enough for healthy plant growth, and it contains some dangerous chemicals called perchlorates, which are used on Earth in fireworks and explosives.
Cleaning the regolith and turning it into something living would not be easy. What the alien soil needs is a Martian fertilizer, perhaps made by adding extremophiles – hardy microbes imported from Earth that can survive even in the harshest conditions. Genetically modified organisms are also a possibility.
Through photosynthesis, these organisms would begin converting carbon dioxide into oxygen. As Mars eventually became more hospitable to Earth-like organisms, colonists were able to introduce more complex plants and even animals.
Providing oxygen, water and food in the right amounts is extraordinarily complex. On Earth, scientists have tried to simulate this in Biosphere 2, a closed ecosystem with ocean, tropical and desert habitats. Although all the environments in Biosphere 2 are controlled, even there scientists struggle to find the right balance. Mother Nature really knows what she’s doing.
A house on Mars
Buildings could be 3D printed, but first they would need to be pressurized and protected until Mars reaches Earth-like temperatures and air conditions. NASA’s Moon-to-Mars Planetary Autonomous Construction Technologies program is researching exactly how this can be done.
There are many other challenges. For example, unlike Earth, Mars does not have a magnetosphere to protect the planet from solar wind and cosmic radiation. Without a magnetic field, too much radiation gets through for living things to remain healthy. There are ways to create a magnetic field, but so far the science is still very speculative.
In fact, all of the technologies I have described are far beyond the current capabilities required to terraform Mars. Their development would require enormous amounts of research and money, probably much more than is possible in the near future. Although the Genesis device from Star Trek III could terraform a planet in a matter of minutes, terraforming Mars would take centuries or even millennia.
And before we start turning Mars into a second Earth, many ethical questions need to be addressed. Is it right to change another planet so drastically and permanently?
If all this disappoints you, don’t be disappointed. As scientists develop innovations to terraform Mars, we will also use them 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 very technology to print homes here on Earth – which will help solve the world’s housing shortage.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
