Is it possible to make Mars like Earth?

An artist's impression of a terraformed Mars. Credit: National Geographic/YouTube.

Is it possible that we could one day make Mars like Earth? – Tyla, 16, Mississippi

When I was in high school, my biology teacher showed our class the science fiction movie “Star Trek III: The Search for Spock.”

The plot grabbed me with its description of the “Genesis Project,” a new technology that transformed a dead alien world into one teeming with 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.

Fast forward to today and I am an engineer and a professor developing technologies to extend human presence beyond Earth.

For example, I'm working on advanced propulsion systems to take spacecraft beyond Earth orbit. I'm helping develop lunar construction technologies to support NASA's goal of Long-term human presence on the MoonAnd I was on a team that showed how to 3D print habitats on Mars.

Sustaining people off Earth will take a lot of time, energy and imagination, 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, to transform it so that it resembles Earth and supports life? Or are these just science fiction musings?

To live on Mars, humans will need liquid water, food, shelter, and an atmosphere with sufficient oxygen to breathe and thick enough to retain heat and protect against the sun's radiation.

But The Martian atmosphere It is composed almost entirely of carbon dioxide, with virtually no oxygen. And it is very thin: only 1% of the density of Earth.

The less dense an atmosphere is, the less heat it can retain. Earth's atmosphere is thick enough to retain enough heat to support life, as far as we know. like the greenhouse effect.

But on Mars the atmosphere is so thin that nighttime temperatures routinely drop to minus 150 degrees Fahrenheit (minus 101 degrees Celsius).

So what's the best way to give Mars an atmosphere?

Although Mars does not have any active volcanoes at present, at least as far as we know, scientists could trigger volcanic eruptions using nuclear explosions. Gases trapped deep within the Martian atmosphere could cause volcanic eruptions to occur. In a volcano would be released and then drift in the atmosphereBut that plan 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. That would also release gases from beneath the planet's surface into the atmosphere, while also releasing the water found in comets. NASA has already shown that It is possible to redirect asteroids – but relatively large measures and large numbers are needed to make a difference.

Making Mars welcoming

There are numerous ways to warm the planet. For example, gigantic mirrors, built in space and placed in orbit around Mars, could Reflect sunlight onto the surface and heat it up.

A recent study proposed that Mars colonists could expand aerogelan ultralight solid material, above ground. The aerogel would act as an insulator and trap heat. This could be done all over Mars, including the polar ice caps, where the aerogel could melt existing ice to produce liquid water.

To grow food, you need land. On Earth, The soil is composed of five ingredients:minerals, organic matter, living organisms, gases and water.

But Mars is covered by a layer of loose, dusty material called regolithThink of it like Martian sand. Regolith contains few nutrients — not enough for healthy plant growth — and harbors some nasty chemicals. called perchloratesused on Earth in fireworks and explosives.

Cleaning up regolith and turning it into something viable It wouldn't be easy. What alien soil needs It's some Martian fertilizermaybe done by adding extremophiles to him – resistant microbes imported from Earth that can Survive even the harshest conditionsGenetically modified organisms are also a possibility.

Through photosynthesisThese organisms would begin to convert carbon dioxide into oxygen. Over time, as Mars became more conducive to life by Earth-like organisms, colonizers might introduce more complex plants and even animals.

Providing oxygen, water and food in the right proportions is extraordinarily complex. On Earth, scientists have tried to simulate this In Biosphere 2a closed ecosystem that includes ocean, tropical and desert habitats. Although all environments in Biosphere 2 are controlled, even there scientists struggle to achieve the right balance. Mother Nature really knows what she's doing.

A house to make Mars like Earth

The buildings could be 3D printed, but would initially need to be pressurized and protected until Mars reaches Earth-like temperatures and air. Autonomous planetary construction technologies from the Moon to Mars The program is investigating how to do exactly this.

There are many more challenges. For example, Unlike EarthMars does not have magnetospherethat shields a planet from solar wind and cosmic radiation. Without a magnetic field, too much radiation passes through for living things to remain healthy. Ways to create a magnetic fieldBut so far the science is highly speculative.

In fact, all of the technologies I have described are far beyond current capabilities at the scale needed to terraform Mars. Developing them would require enormous amounts of research and money, probably far more than is possible in the near term. While 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 there are many ethical questions to be resolved before people start turning Mars into another Earth. Is it right to make such drastic and permanent changes on another planet?

If all of this leaves you disappointed, don’t be discouraged. As scientists create innovations to terraform Mars, we will also use them to improve life on Earth. Remember the technology we are developing to 3D print habitats on Mars? Right now, I am part of a group of scientists and engineers using that same technology to print homes here on Earth, which will help address the problem of air pollution. housing shortage in the world.

This article was First published on The ConversationRepublished here under a Creative Commons license.