alive. It looks like we'll only ever have small  crews spend a miserable time hidden underground.  

Except, we could terraform it into a green  new world. But to solve the planet's problems,  

we first need to make it worse and turn it  into oceans of lava with gigantic lasers.

This isn't a far-fetched science fiction tale.  Terraforming Mars is possible, on the kind of  

time scale our ancestors built great monuments  in. If humanity solves some of its pressing  

problems and ventures into space to expand into  the solar system, this may not be that far off.

Ok. So how do we terraform Mars  quickly? Well, It's complicated.

Mars is dry and has no soil to grow anything. Its  atmosphere is too thin to breathe or protect from  

radiation, giving you a high risk of cancer.  So to turn it into a new home for humanity,  

we have to give it a proper atmosphere, similar  to Earth's. It should be made of 21% oxygen,  

79% nitrogen and a tiny bit of CO2, at an average  temperature of 14°C and under 1 bar of pressure.

We have to create oceans and rivers and then the  ground has to be weathered into fertile soil to  

host living things. Then we need to install  a biosphere on the surface and prevent it all  

from being undone by installing protective  measures that can stand the test of time.

It's difficult. But a big  laser makes it a lot easier.

Challenge 1: The Atmosphere

Some 4 billion years ago Mars had a nice  oxygen-rich atmosphere and was home to vast  

oceans and rivers. It held onto it for  several hundred million years before it  

got blown away. Ultraviolet rays broke down  the atmospheric gases and then the oceans,  

until they were swept away by solar wind.  Today Mars is a dry, barren wasteland.

Luckily a sizable portion of the water is frozen  in deep reservoirs and in the polar ice caps,  

enough to create a very shallow ocean.  And enormous amounts of oxygen are bound  

as minerals in the Martian rocks,  like the oxygen in the iron oxides  

that give the planet its rust-red colour,  as well as carbon dioxide in carbonates.

To free these gases, we need to  reverse the reactions that lock  

them away by using thermolysis,  which occurs at temperatures as  

high as on the surface of the Sun. In  short, we want to melt Mars' surface.

The best way to do that would be to put lasers  in orbit aiming their beams down on Mars.  

The most powerful laser today is the ELI-NP,  

able to produce beams of 10 Petawatts  of power, for a trillionth second.

To melt Mars we need a laser twice as powerful,  that runs continuously. The easiest way is to use  

a solar-pumped laser that can be powered directly  with sunlight: At its core are metal-infused glass  

rods that absorb energy and release it as a laser  beam. If we build an array of mirrors in space,  

about 11 times the size of the United States, we  can focus enough sunlight onto them to melt Mars.

Let's do it!

As the lasers hit the surface, about 750  kg of oxygen and some carbon dioxide emerge  

from every cubic meter of rock melted. If  we are efficient our lasers only need to  

melt through the top 8 meters of  the surface to get enough oxygen.

It would look terrifying. The  skies would be shrouded in storms,  

while the ground would glow red-hot,  criss-crossed by currents of lava.  

Tireless laser beams sweep over the landscape,  leaving trails too bright to look at. After they  

pass, the ground cools quickly. A strange  snow falls: the ashes from all the elements  

that solidify as they cool down, like silicon and  iron. Mars is still a cold planet at this point.

A happy side effect of this inferno is that  all the water in the polar ice caps and even  

deep underground rises into the sky as hot  steam, forming clouds that rain down over  

the entire planet. They would wash out  the nastier gases from the atmosphere,  

like chlorine, and carry away harmful elements  that accumulated on the surface. In the end, they  

would form shallow oceans, saltier than on Earth.  We might need to do an extra clean-up afterwards.

It would take about 50 years of continuous  lasering to create our oxygen atmosphere. We  

could use this opportunity to dig deeper in some  places to create the basins for salty oceans or  

rivers and spare some landmark features  like Mons Olympus and Valles Marineris.

We're not done though.

The resulting atmosphere is nearly 100%  oxygen and only 0.2 bar. It's hard to  

breathe and very flammable. To make  it similar to earth and a lot safer,  

we need to add a lot of nitrogen, which  Mars is lacking sadly. We have to import it.

The ideal source is Titan, a large moon of Saturn,  covered in a thick atmosphere that's almost  

entirely nitrogen. We just have to move 3000  trillion tons from the outer solar system to Mars.

While that's not easy, it is doable. To  process that much of Titan's atmosphere,  

we have to construct giant automated factories,  on its surface powered by our lasers to suck in  

the atmosphere and compress it into a liquid.  This gets pumped into bullet-shaped tanks,  

which a mass driver shoots all the way to  the red planet, where they explode and mix  

with the oxygen. We've already been able to send  individual missions to Saturn in just a few years.  

With enough resources, it should be possible  to complete the task within 2 generations. 

Of course it would be much more  convenient to have nitrogen left  

over from terraforming Venus on the side: we  explained this in detail in another video.

So, about a century after the  start of the terraforming process,  

we have a breathable atmosphere that has  the right gases. If the liberated CO2  

isn't enough to warm it up to temperatures we  can stand, we just add some super greenhouse  

gases. Mars at this point resembles a  black marble from all the cooling lava,  

spotted with growing oceans and red patches  where the old surface remains untouched. It's  

still a wasteland, no better than a desert  on Earth. We need to fill it with life.

Challenge 2: Biosphere

Installing a biosphere on a new planet is  very difficult. Unexpected interactions  

between species or sudden diseases can  destabilise it to the point of collapse.

We would probably begin by seeding our young  oceans with phytoplankton. Without competition,  

it would bloom rapidly, filling up the oceans  to become the bottom of an aquatic food chain.  

They can be followed by tiny zooplankton,  

then by fish. Maybe even sharks and whales. If  things go well, life in the oceans will thrive.

Life on land is harder. Plants need  nutrient-filled ground to sink their roots  

into. But most of the surface is the congealed  remains of lava and ashes. We could wait for  

thousands of years for water and wind to grind it  down into finer sands or try to do it manually.

But we want to be quick. And we have a  big laser. Turning the beam on and off  

in rapid succession would cause the ground to  quickly heat up and contract, which breaks it  

into smaller and smaller pieces. Add a bit  of water, and you get a sort of dark mud.

Into this mud, we can mix fungi and  nitrogen-fixing bacteria. They're  

able to absorb nitrogen and convert it  into nitrate compounds to feed plants.  

The first plants we want to bring are  native to volcanic islands on Earth,  

since they are perfectly suited to  the laser-blasted Martian landscape.

Eventually, the enriched mud becomes the  foundation for grasslands and forests. In  

Mars' lower gravity, trees can become very tall  very fast. Their roots gather the nutrients  

they need and then dig deeper to turn more rocks  into soil, forming a self-sustaining ecosystem.

At this point we can slowly introduce more plant  varieties, insects and animals. Not mosquitoes  

though. The new biosphere needs to be maintained  to prevent it from falling out of balance. If  

plants grow too quickly and absorb too much  carbon dioxide, the planet cools down too much.  

If key species die out, we could see populations  collapse faster than they could recover. On Earth,  

other species would move in to fill the void,  but our Martian biosphere is not as flexible.

It takes hundreds if not thousands of years  before Mars becomes a stable environment.

But eventually the planet will have the potential  to sustain large human colonies. With air,  

water and food available, we  can finally call Mars – black,  

blue and green – our home. A  giant, volcanic island in space.

Will it last though?

Challenge 3: The long-term future

There is a problem we haven't addressed: Mars'  core does not produce a magnetic field, so it does  

not have enough protection from solar radiation  or cosmic rays. This becomes dangerous for the  

long term health of Martian populations. So as a  final step, we need an artificial magnetic field.

It doesn't have to be huge like Earth's. It  

just needs to deflect the solar wind  enough so that it doesn't touch Mars.

The easiest way is to construct a magnetic  umbrella far ahead of Mars that splashes the solar  

wind to the sides. A big, superconducting ring  powered by nuclear facilities is all it takes.  

It would orbit at the Mars-Sun L1  point, keeping it constantly in  

between the Sun and Mars and protect  the new atmosphere. And that's it!

Terraforming Mars would take some work,  hefty resources and probably a century or  

ten but it would be the first time  we've lived in a home designed and  

shaped solely by us and for us. A first  step towards our future among the stars.

The first step we can already take  down on Earth is learning more about  

the physics and biology needed for such a project.

To help you with that, we've created a series of  lessons to build your fundamental understanding  

of these topics. Made in collaboration  with our friends at Brilliant.org,  

these lessons give you a deeper understanding  of the topics from our most popular videos,  

from supervolcanoes to black  holes to climate science.

Brilliant is an interactive learning tool  that makes math, science, and computer  

science accessible with a hands-on approach.  Because we know that to really learn something,  

you've got to do it. Think of each lesson as a  one-on-one tutoring version of a Kurzgesagt video.

In our latest lesson, you'll learn more  about how Mars lost its atmosphere and  

how we might protect a terraformed  Mars from suffering the same fate.

Brilliant has thousands of lessons to explore—from  math-based topics like algebra and probability  

to the concepts behind algorithms and machine  learning. And with new lessons added each month,  

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To get hands-on with Kurzgesagt lessons and  explore everything Brilliant has to offer,  

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