Why Is "IMPOSSIBLE" For Humans To Reach Mars | Neil Degrasse Tyson

In 2013, a Dutch company called Mars 1 announced they were accepting applications for a one-way trip to Mars. No return ticket. You go, you stay, you die there.

200,000 people signed up. Think about that. 200,000 human beings looked at the proposition of leaving Earth forever, never seeing their families again, never breathing fresh air, never feeling rain on their face or swimming in the ocean, and said, "Yes, sign me up.

I'm in. " A woman named Sonia Van Meter, a political consultant from Texas with a husband, two stepsons, and a black lab, made the final hundred candidates. She wrote an essay explaining why she volunteered.

She said, "Space exploration is worth a human life. Every astronaut who has ever flown has known the risks. " She wasn't being dramatic.

She was being honest. Mars One went bankrupt in 2019 without sending anyone anywhere. The company was, let's be charitable, a masterclass in how not to plan a space mission.

But those 200,000 applications, those were real. Those represented something deep and true about human nature. The desire to touch another world, even at the cost of everything.

So, let me tell you why that desire, as powerful as it is, keeps running headfirst into a wall called physics. Let me tell you why Mars is so hard that it makes the moon landings look like a practice run. And let me tell you why.

Despite everything I'm about to say, I still believe humans will eventually walk on that red soil. But first, let's talk about distance because I don't think most people really understand the distance. When Apollo 11 went to the moon, the astronauts traveled about 240,000 mi.

That's far. That's further than any human had ever gone. It took them 3 days to get there.

Three days of coasting through the void. And then they were standing on another world. Mars at its closest approach is 140 million miles away.

Let me help you visualize that. If the Earth and Moon were a foot apart, Mars would be a mile away. If the moon trip was a walk to your mailbox, Mars is a drive from New York to Los Angeles and back twice.

But here's what makes it worse. The moon is always roughly the same distance from Earth. Mars isn't.

Because both Earth and Mars orbit the Sun at different speeds, the distance between them varies wildly. At closest approach, it's about 34 million miles. At its farthest, 250 million miles.

The cosmic geometry is constantly shifting. This means you can't just go to Mars whenever you want. You have to wait for the planets to align correctly, which happens roughly every 26 months.

Miss that launch window, and you're waiting over 2 years for the next one. The universe doesn't care about your schedule. And here's the real kicker.

Even with optimal timing, a one-way trip to Mars takes 7 to 9 months using conventional rockets. Not days, months. The entire journey to the moon and back took eight days.

A Mars mission round trip takes two to three years minimum. You fly there for seven months. You wait on the surface for over a year until the planets align again.

You fly back for another 7 months, 2 to 3 years, away from Earth, away from everyone and everything you've ever known. Now in 1995, a Russian cosminaut named Valeri Polyov returned to Earth after spending 437 consecutive days on the Mir space station. 14 and 1/2 months in orbit.

When they opened the hatch of his landing capsule in the frozen steps of Kazakhstan, the medical team rushed forward to carry him out. Standard procedure. After that long in microgravity, most cosminauts can barely stand.

Palakov waved them off. He climbed out of the capsule on his own two feet, walked to a nearby chair, sat down, lit a cigarette, and drank a glass of brandy. When asked why he insisted on walking, he said, "That was pretty much the goal of the flight.

I had to show that it is possible to preserve your ability to function after being in space for such a long time. " The whole point of his mission was to simulate a trip to Mars. To prove that humans could survive the journey and still function when they arrived.

And in some ways, he succeeded. He walked out of that capsule. He didn't die.

He didn't lose his mind. But here's what the vodka and cigarette moment doesn't tell you. Polyakov grew two and a half inches during his flight.

His spine, freed from gravity, stretched out. This made his custom fitted re-entry seat extremely uncomfortable on the way down. He lost bone density.

He lost muscle mass. His cardiovascular system deconditioned and Polyov was in low Earth orbit, still protected by Earth's magnetic field from the worst cosmic radiation, still able to see his home planet every 90 minutes, still connected to ground control in real time, still theoretically hours away from rescue if something went catastrophically wrong. A Mars crew gets none of that protection, none of those psychological comforts, none of those safety nets.

The moment you leave Earth orbit for Mars, you enter the most hostile environment humans have ever deliberately tried to survive. And I'm not being hyperbolic. Space between Earth and Mars will actively try to kill you in ways you've probably never considered.

Let's start with radiation because this is the one that keeps mission planners up at night. Here on Earth, you're protected by two invisible shields. First, the atmosphere, which absorbs most incoming cosmic radiation.

Second, and more importantly, Earth's magnetic field. Our planet has a molten iron core that generates a massive magnetosphere extending thousands of miles into space. This magnetic bubble deflects charged particles from the sun and from deep space.

Without it, life on Earth's surface would be impossible. The moment you leave low Earth orbit, you lose that protection. You're exposed to two types of radiation that are extremely difficult to shield against.

First, solar particle events. The sun periodically erupts with massive explosions that accelerate protons to nearly light speed. These solar storms are unpredictable and can be lethal to unprotected humans.

The Apollo astronauts were lucky. They flew during a quiet solar period, and their missions were so short that the odds of encountering a major storm were low. A Mars crew traveling for years is virtually guaranteed to experience multiple solar events.

Second, and this is the worst one, galactic cosmic rays. These are particles from outside our solar system, accelerated by supernova and other violent cosmic events to incredible energies. These particles are so energetic that they can penetrate several feet of solid material.

They pass through spacecraft holes like they're not even there. They pass through your body, damaging DNA along the way. You can't really shield against galactic cosmic rays.

Not with any practical amount of material. The best you can do is minimize exposure time, which is why some researchers are working on faster propulsion systems. But with current technology, a round trip to Mars exposes astronauts to 600 to 1,000 milliseverts of radiation.

NASA's career limit for astronauts is 1,000 milliseverts. A single Mars mission could use up your entire lifetime allowance. And we're still not sure what the long-term health consequences will be.

Some studies suggest elevated cancer risk. Others indicate potential cognitive effects, what researchers call space brain, where high energy particles damage neurons and potentially impair memory, decision-m, and emotional regulation. Imagine being eight months into a Mars journey, dealing with equipment malfunctions and interpersonal conflicts while cosmic rays are slowly degrading your brain's ability to think clearly.

This isn't science fiction. This is a real challenge that real engineers are trying to solve right now, and they haven't solved it yet. So, when someone tells you, "We're going to Mars in 5 years," ask them about the radiation.

Ask them specifically how they plan to protect the crew from galactic cosmic rays for a three-year mission. If they don't have a detailed answer, they're selling you a fantasy. But radiation is just one problem.

And honestly, it might not even be the biggest one. Because the real killer, the thing that dominates every aspect of Mars mission planning is something called the rocket equation. In 1903, a Russian school teacher named Constantine Siokovski figured out something that would haunt rocket engineers for the next century.

He derived a simple equation that describes how rockets work. And that equation is brutal. Here's the basic problem.

A rocket moves by throwing mass out the back. That's Newton's third law, action and reaction. You throw exhaust one direction, the rocket moves the other direction.

Simple enough. But the fuel you need to accelerate your spacecraft is itself mass that must be accelerated. So you need fuel to move your fuel.

And you need more fuel to move the fuel that moves your fuel. The relationship is exponential, not linear. To go twice as fast doesn't require twice as much fuel.

It requires far far more. Let me give you a concrete example. The Saturn 5, the rocket that took us to the moon, was and remains the most powerful machine ever successfully operated by humans.

At launch, it weighed 6 12 million pounds. 85% of that was fuel. The rocket consumed 20 tons of propellant per second at liftoff.

In the first 11 minutes of flight, it burned through 2,800 tons of fuel. And what did all that fury deliver to the moon? about 50 tons.

That's a ratio of roughly 130 to one 130 pounds of rocket and fuel for every pound delivered to the lunar surface. For Mars, the ratios are worse, much worse, because Mars is further away. And because you need to carry enough supplies for a multi-year mission and because you need fuel for the return trip, here's a rough breakdown of what a crude Mars mission requires.

You need a crew habitat. The spacecraft where six astronauts will live for 7 to n months traveling to Mars. It needs radiation shielding, life support systems, exercise equipment, food storage, medical facilities, redundant backups for everything critical.

Call it 40 to 50 metric tons. You need a propulsion system. The rockets and fuel that will push this habitat out of Earth orbit and onto a Mars trajectory.

For chemical rockets, this means two to three times the mass of the payload in propellant. Another 100 metric tons minimum. You need a Mars landing vehicle.

Something that can deliver the crew from Mars orbit to the surface with heat shields, parachutes, landing rockets, another 20 to 30 metric tons. You need a surface habitat. Where will the crew live for 16 months on Mars?

They need shelter, power generation, water processing, oxygen production, another 30 to 50 metric tons. You need an ascent vehicle, a rocket to launch the crew from Mars back into orbit, plus the fuel for that rocket, which either has to be manufactured on Mars or carried from Earth at enormous cost. Another 30 to 50 metric tons just for the vehicle, potentially over a 100 tons if you're bringing the fuel.

You need a return vehicle. The spacecraft that brings the crew home with propulsion, life support for another seven months, and a heat shield for Earth re-entry. Another 30 to 40 metric tons.

Add it all up and you're looking at 300 to 500 metric tonses that need to reach Mars. And because of the rocket equation, every kilogram sent to Mars requires roughly 10 to 20 kg launched from Earth. That means a single crude Mars mission requires launching somewhere between 3,000 and 10,000 metric tonses from Earth's surface.

That's equivalent to multiple International Space Stations. The ISS took over 40 launches and a decade to assemble and it masses only about 420 tons. Now you understand why Mars is so hard.

It's not one problem. It's the cascading multiplication of many problems all governed by the tyranny of the rocket equation. SpaceX is building something called Starship, which is designed to carry about 100 tons to low Earth orbit and potentially be fully reusable.

If it works as advertised, it would be the most capable launch system ever built. And it would still require multiple launches and orbital assembly operations to mount a Mars mission. Elon Musk talks about this.

He understands the rocket equation intimately. His Raptor engines, which power Starship, use methane and liquid oxygen as propellant. This is deliberate because the carbon dioxide in Mars' atmosphere and the water ice on Mars can theoretically be processed into methane and oxygen.

The idea is to manufacture your return fuel on Mars instead of carrying it from Earth. This concept is called INC2 resource utilization or ISRU. It's elegant.

It's potentially game-changing. And it's never been done. The Perseverance rover has a small experiment called Moxy that has successfully produced tiny amounts of oxygen from the Martian atmosphere, about 10 g per hour.

A human crew would need something like 2 to 3 kg of oxygen per person per day just to breathe, plus vastly more for rocket fuel. Moxy is proof of concept. scaling it up by a factor of thousands, making it reliable enough to bet astronauts lives on, building the power systems to run it.

That's still science fiction. Every serious Mars mission plan includes ISRU. It's baked into the mass calculations.

If it doesn't work, if the equipment fails, if production rates are lower than expected, the mission fails. Astronauts could be stranded on Mars without enough supplies to survive until the next launch window, without enough fuel to return home. This is not a hypothetical risk.

This is a fundamental dependency in every Mars architecture ever proposed. And we haven't even talked about cost yet. NASA's annual budget is about $25 billion.

That sounds like a lot until you realize it's less than half a percent of the federal budget. less than Americans spend on pizza every year. The Apollo program cost about $25 billion in 1,960 seconds money adjusted for inflation.

That's somewhere between 150 and $200 billion today. And Apollo was a sprint, a crash program with essentially unlimited funding driven by cold war competition. At peak Apollo, NASA received 4% of the federal budget.

Today, it's less than half a percent. Realistic estimates for a human Mars program range from 200 billion to over a trillion dollars, depending on scope and timeline. At current funding levels, that's NASA's entire budget for 8 to 40 years.

That's obviously not how it would work. You'd need sustained increases over multiple decades, multiple administrations, multiple congresses. And here's the political reality.

Space programs are easy to start and easy to cancel. A president announces a bold initiative, gets credit for the vision, and moves on. The next president, facing budget realities, restructures or cancels the program.

This has happened over and over. The space exploration initiative cancelled. Vision for space exploration restructured beyond recognition.

constellation program cancelled. The space launch system has been in development for over a decade and flown once. A Mars program would need to survive 20 to 30 years of development, five to seven presidential administrations, a dozen congresses, economic recessions, international crises, competing priorities.

The Saturn 5, the rocket that got us to the moon, we stopped building it in 1970, closed the factories, let the engineers retire or move on, lost the institutional knowledge. If we wanted to build another one today, we'd essentially be starting from scratch. So when I express skepticism about humans reaching Mars in the next decade, it's not because I doubt human capability.

We can do this. The physics allows it. The engineering is difficult but not impossible.

What I doubt is our collective ability to sustain the commitment required to maintain focus across decades to keep funding a program through multiple political cycles when there are always more immediate problems demanding attention. Mars requires patience. Mars requires persistence.

Mars requires the kind of civilizational dedication we've rarely demonstrated except under threat of war. And maybe that's what we need. Maybe we need a space race.

China has announced plans for crude Mars missions in the 2030s and 2040 seconds. Maybe competition will do what inspiration alone cannot. Because here's the truth.

The physics is solvable. The engineering is solvable. Even the money is solvable.

If we decide it matters enough, the question is whether we'll decide. Let's say you make it 7 months of cosmic radiation, 7 months of bone loss and muscle atrophy, 7 months of recycled air and recycled water in the same six phases. But you're alive.

You're approaching Mars. The red planet fills your window. Rustcoled and ancient waiting.

Now comes the part NASA engineers call 7 minutes of terror. You enter the Martian atmosphere traveling at about 12,500 mph. That's Mach 16.

In 7 minutes, you need to slow down to zero and touch down gently on the surface. Too fast, you crash. Too slow, you run out of fuel before landing.

The margin for error is razor thin. And here's what makes it terrifying. You're on your own.

Radio signals travel at the speed of light, but Mars is so far away that there's a communication delay of 4 to 24 minutes, depending on planetary positions. By the time mission control receives your signal that you've entered the atmosphere, you're already on the ground or in the ground. The entire landing sequence has to happen autonomously, controlled by onboard computers with no help from Earth.

If something goes wrong, no one can save you. Now, here's what makes Mars uniquely difficult to land on. It has an atmosphere, but barely.

Earth's atmosphere is dense enough that you can use parachutes to land. The moon has no atmosphere, so you can use rockets the whole way down without worrying about aerodynamics. Mars is the worst of both worlds.

The atmosphere is thick enough that you have to deal with it. You can't ignore it, or your spacecraft will be destroyed by friction and heat, but it's too thin to slow you down with parachutes alone. Mars' atmospheric pressure is about 1% of Earth's.

1%. If you deployed a parachute the size of a football field, it still wouldn't slow a heavy spacecraft enough to land safely. After the parachute does what it can, you're still traveling at hundreds of miles hour.

You need rockets to finish the job. The largest thing we've ever landed on Mars is the Curiosity rover, about 1 metric ton. The landing system was so complex involving a heat shield, a supersonic parachute, retro rockets, and a sky crane that lowered the rover on cables while hovering.

That the engineers who designed it called it crazy. Tom Rivllini, one of the lead engineers, said Mars is actually really hard to slow down because it has just enough atmosphere that you have to deal with it otherwise it will destroy your spacecraft. On the other hand, it doesn't have enough atmosphere to finish the job.

A human mission requires landing 40 to 80 metric tons on Mars. That's 50 to 80 times more mass than Curiosity. The parachutes would need to be impossibly large.

The heat shields would need to be enormous. We don't have proven technology to do this. The leading concept is called supersonic retropulsion.

firing rockets while still traveling faster than sound to slow the spacecraft enough for a controlled descent. SpaceX has demonstrated this on Earth with their Falcon 9 boosters. Those landing videos you've seen, the rocket coming down on a pillar of fire to touch down on a pad or a drone ship, that's supersonic retropulsion.

But Earth is not Mars. The atmosphere is different. The gravity is different.

The consequences of failure are absolute. And no one has ever done it with a spacecraft large enough to carry humans and their supplies. If the system fires too early, you run out of fuel.

If it fires too late, you hit the ground too fast. If the shock waves from the rockets destabilize the spacecraft, you tumble and crash. There are failure modes we haven't even identified yet cuz no one has tried this at scale.

And remember, the crew has been degraded by 7 months of space flight. They're weaker. Their bones are more brittle.

Their coordination may be impaired. They're descending through the atmosphere of an alien world, hoping the automated systems work perfectly, unable to do much if they don't. 7 minutes, no help from Earth.

Everything has to work. Now, let's say the landing succeeds, the dust settles, the engines shut down. You've done it.

You're on Mars. Welcome to hell. Let me describe what you've landed on.

Because Mars is not a cold desert. Mars is not like Antarctica. Mars is actively trying to kill you in ways that Earth never does.

Start with the atmosphere. Or rather, the near complete absence of one. The pressure on Mars is about 6 millibars.

Earth's sea level pressure is 1,13 millibars. That's less than 1%. At that pressure, if you were exposed without a suit, the liquid in your eyes and mouth would begin to boil.

Not from heat, from the pressure being so low that water vaporizes at body temperature. You would be dead in seconds. And even if pressure weren't an issue, the composition would kill you.

Mars' atmosphere is 95% carbon dioxide, less than half a% oxygen. You cannot take a single breath of Martian air ever for your entire stay on the planet. Every breath you take must come from systems you brought with you or manufactured on site.

The thin atmosphere also provides almost no protection from radiation. Remember those cosmic rays we talked about earlier? On Earth, the atmosphere provides shielding equivalent to about 30 ft of water.

On Mars, almost nothing. The radiation environment on the Martian surface is about 50 times higher than on Earth. Every day on Mars increases your cancer risk.

And Mars has no global magnetic field. Whatever magnetic protection Earth provides, Mars provides essentially none. The planet's core cooled and solidified billions of years ago.

There's nothing between you and the cosmos except that pathetically thin atmosphere and whatever shielding you can construct. Now, let's talk about temperature. The average temperature on Mars is about -80° F.

At the poles in winter, it drops to - 195. Even at the equator in summer, nighttime temperatures regularly plunge below minus 100, and the temperature swings are extreme. In a single day, temperatures can vary by over 150 degrees.

Your habitat has to handle these extremes. Your suit has to handle them when you go outside. Every seal, every mechanism, every electronic component has to function at temperatures that would shatter most Earth materials.

And then there's the soil. In the 1970s, the Viking landers conducted experiments to search for life on Mars. One experiment added nutrients to soil samples and looked for biological activity.

What they found was puzzling. There was a strong chemical reaction, but it didn't look like biology. It looked like chemistry.

Decades later, we figured out what was happening. Martian soil contains significant concentrations of perchlorates. These are chlorine-based compounds that are highly oxidizing and toxic to humans.

They interfere with thyroid function. They damage cells and they're everywhere on Mars. Globally distributed across the surface.

This means the dust that will inevitably get into your habitat, onto your equipment, into your food preparation areas, is not just annoying, it's poison. Long-term exposure could cause serious health problems. And there's no escaping the dust.

Mars has dust storms that can engulf the entire planet and last for months. In 2018, a global dust storm killed the Opportunity rover by coating its solar panels and blocking sunlight. So, let me summarize what you've landed on.

A planet with essentially no atmosphere, where unprotected exposure means instant death. What atmosphere exists is 95% carbon dioxide. The soil is toxic.

The radiation would give you cancer. The temperature regularly drops below 100° below zero. There's no liquid water, no food sources, no breathable air, no magnetic protection, and you have to survive there for 16 months before you can even begin the journey home.

This is not like any environment humans have ever tried to inhabit. Antarctica is a paradise compared to Mars. The bottom of the ocean is more hospitable.

The inside of a nuclear reactor is more welcoming. And yet, people still want to go. Despite everything I've just told you, there are thousands of people, serious people, accomplished scientists and engineers, who would volunteer tomorrow.

That tells you something about human nature, something important. Your body is a machine built for Earth. 60 million years of primate evolution, 4 million years of homminid evolution, 300,000 years of homo sapiens evolution.

All of it happened here at 1g of gravity protected by a magnetic field breathing 21% oxygen at sea level pressure. Take any of those away and systems start failing. I told you about Valeri Polyov, the Russian cosminaut who spent 437 days on Mir.

I told you he walked out of the capsule on his own, lit a cigarette, drank a brandy. What I didn't tell you is what happened to his body during those 14 months. He grew 2 and 1/2 in because his spine, no longer compressed by gravity, stretched out.

This is not a good thing. When he returned to Earth, his vertebrae had to recompress, which is painful and can cause long-term problems. He lost bone density about 1 to 2% per month.

After 14 months, that's potentially 20% or more of his bone mass gone, dissolved and excreted because his body decided it didn't need all that heavy calcium anymore. On Earth, this bone loss is associated with osteoporosis, increased fracture risk, reduced mobility. He lost muscle mass.

Without gravity constantly forcing muscles to work, they atrophy rapidly. Astronauts can lose up to 20% of muscle mass on long missions despite exercising 2 hours every day. 2 hours.

That's a full gym session every single day just to slow the deterioration. His cardiovascular system deconditioned. On Earth, your heart works constantly to pump blood against gravity.

In space, that effort becomes unnecessary. The heart adapts by becoming weaker. Blood pressure regulation changes.

Many astronauts experience orthostatic intolerance when they return, meaning they struggle to stand without feeling faint. His eyes change shape. This one surprised everyone.

Many astronauts returning from long missions have vision problems. The fluid shift toward the head that happens in microgravity increases pressure inside the skull, which presses on the optic nerve and deforms the eyeball. Some astronauts have come back needing glasses who had perfect vision before.

Some have permanent damage. We don't fully understand this syndrome. We don't have a good way to prevent it.

Polyakov was on the International Space Station, which orbits at about 250 mi altitude. He was still within Earth's protective magnetosphere. He could see his home planet every 90 minutes.

He had regular resupply missions, bringing fresh food and psychological boosts. He could communicate with family and ground control in real time. A Mars crew gets none of that.

The journey to Mars takes 7 to N months. During that time, astronauts experience all the physiological degradation I just described, plus exposure to cosmic radiation that ISS astronauts are largely protected from. They arrive at Mars weaker than when they left with less bone density, less muscle mass, compromised cardiovascular function, and potentially impaired vision.

Then they have to land a spacecraft. Then they have to function on a planet with 38% Earth gravity, which sounds easier, but actually creates problems. The body has adapted to zero gravity.

Now it has to readapt to partial gravity. This transition is disorienting and exhausting. Then they have to work, set up habitat, maintain equipment, conduct scientific research, possibly construct additional infrastructure, do all of this while continuing to lose bone and muscle because Mars gravity isn't strong enough to reverse the process completely.

Then they have to spend 16 months on the Martian surface waiting for the planets to align for the return journey. 16 months of continued physiological stress, 16 months of radiation exposure, 16 months of toxic dust infiltrating everything. Then they have to launch from Mars, spend another 7 to 9 months in zero gravity, enduring further deterioration, and finally re-enter Earth's atmosphere and land.

By mission end, astronauts could have lost 30% or more of their bone density. They could have severe muscle atrophy. Their cardiovascular systems will be severely deconditioned.

They may have permanent vision damage. They will have received radiation doses near or exceeding lifetime safety limits. And here's what really concerns me.

We don't know if these effects are fully reversible. Studies of ISS astronauts show that bone density lost in space may not fully recover even years after returning to Earth. The damage appears to be partially permanent.

For a six-month mission, this is acceptable. for three-year Mars mission. We're in unknown territory.

Polyov proved that humans can survive a year and a half in space. What he didn't prove is that humans can survive a year and a half in space, spend another year on Mars, spend another 9 months in space, and return to Earth healthy enough to walk. That experiment hasn't been done.

The Mars mission itself will be the experiment. The first crews will be test subjects discovering in real time what 3 years of extraterrestrial existence does to the human body. Some researchers propose artificial gravity, spin the spacecraft to create centrifugal force that mimics gravity.

In principle, this could prevent much of the physiological degradation. In practice, it's enormously complicated. A spinning spacecraft is harder to control.

Docking becomes more difficult. Any mass imbalance causes problems. The rotation rate needed for Earth equivalent gravity creates corololis effects that cause motion sickness and disorientation.

NASA has studied artificial gravity for decades. No crude spacecraft has ever used it. The engineering challenges remain unsolved.

Other researchers propose pharmaceutical interventions, drugs that prevent bone loss, drugs that stimulate muscle growth, drugs that protect against radiation damage. Some show promise in early studies, but we're talking about taking these drugs continuously for 3 years. The long-term side effects are unknown, and there's something troubling about a mission architecture that requires extensive pharmaceutical support just to keep the crew alive.

Now, let's add psychological factors. Polyakov reported that the hardest part of his mission wasn't the physical challenges. It was the isolation, the monotony.

Watching Earth slide by outside his window, so close he could almost touch it, yet utterly unreachable. Mars astronauts won't have that window. They won't see Earth every 90 minutes.

They'll watch it shrink to a pale blue dot, then disappear entirely behind the sun for portions of the journey. They'll experience communication delays that make real conversation with loved ones impossible. They'll know that if something goes wrong, no one can reach them.

Studies [snorts] of isolated groups in extreme environments show consistent patterns. Interpersonal conflicts intensify. Small annoyances become major grievances.

Depression and anxiety increase. Sleep disorders become common. Cognitive performance degrades over time.

The Soviet space program reported serious psychological issues on long mere missions, conflicts between crew members, conflicts with ground control, episodes of depression and emotional instability, and those cosminauts knew they were hours from rescue if necessary. Mars astronauts will be the most isolated humans in history. The psychological pressure is difficult to overstate.

I'm not saying humans can't handle it. Humans have endured extraordinary conditions throughout history. Polar expeditions, submarine deployments, prisoner of war camps.

We're remarkably adaptable. But we've never asked humans to endure all of these stresses simultaneously for this duration with zero possibility of rescue or abort. The Mars mission will answer questions we've never been able to answer before.

Can humans maintain psychological stability for 3 years of complete isolation? Can the body sustain itself through prolonged exposure to zero gravity, partial gravity, radiation, and toxic environments? Are there limits to human endurance that we haven't yet discovered?

These are not engineering questions. These are questions about what human beings fundamentally are and what we're capable of surviving. And we won't know the answers until someone goes.

So, after everything I've told you, after the radiation and the bone loss and the toxic soil and the impossible distances and the staggering costs, you might reasonably ask, why? Why would anyone volunteer for this? Why should we spend hundreds of billions of dollars and risk human lives to visit a frozen wasteland where nothing can survive without constant technological intervention?

It's a fair question. Let me try to answer it honestly. The practical arguments for Mars are real but limited.

There's the backup planet argument. The idea that humanity needs to become multilanetary to ensure long-term survival. If Earth is hit by an asteroid or suffers some other catastrophic event, having humans on Mars means the species survives.

I understand this argument, but I find it somewhat thin. If you have the technology to make Mars habitable, to create enclosed ecosystems that provide air, water, food, and radiation protection indefinitely, you have the technology to survive almost any catastrophe on Earth. A bunker in Antarctica or underground would be vastly easier than a colony on Mars.

The same technologies that let you live on Mars let you live through nuclear winter or asteroid impact or super volcano eruption. So survival isn't really why we want to go. There's the scientific argument.

Mars is genuinely fascinating. It once had liquid water, maybe rivers and lakes and oceans. It had a thicker atmosphere.

It might have had conditions suitable for life. The question of whether life ever arose on Mars is one of the most profound questions in science. But here's the thing.

Robots do science on Mars very well. Curiosity and Perseverance have conducted extraordinary research. For the cost of one crude mission, you could send dozens of sophisticated robotic probes.

If pure scientific return per dollar is your metric, robots win. So, science isn't really why we want to go either. Not entirely.

I think the real answer is something deeper. Something that doesn't fit neatly into costbenefit analyses or risk assessments. 200,000 people volunteered for a one-way trip to Mars with a company that had no realistic plan to get them there.

That tells you something about human nature that's worth paying attention to. Humans are explorers. It's encoded in our DNA by millions of years of evolution.

Our ancestors walked out of Africa and spread across every continent. They crossed deserts and mountains and oceans. They settled in frozen wastelands and tropical jungles.

They pushed into every environment, no matter how hostile, and found ways to survive. This drive to explore, to push beyond known boundaries, to discover what's over the next hill, is fundamental to who we are. We don't explore because it's practical.

We explore because we can't help ourselves, because the unknown calls to us. Because staying in one place, accepting limits, feels like a kind of death. The moon landings were the most watched events in human history.

Not because people were interested in lunar geology because something about seeing humans walk on another world spoke to something deep in the human spirit. It said we are more than we thought we were. We can do things that seemed impossible.

Mars would be that amplified by orders of magnitude. The moon is close. You can see it with your naked eye.

It takes three days to get there. Mars is genuinely far. A journey to Mars is a journey into the true unknown.

A commitment measured in years. An achievement that would stand as the greatest feat of exploration in human history. In July 2024, four volunteers emerged from a 378day simulated Mars mission at NASA's Johnson Space Center.

They'd lived in a 1,700 ft 3D printed habitat designed to replicate Martian conditions. Limited communication with the outside world. Simulated spacew walks.

Psychological monitoring throughout when they walked out. One of them, a science officer named Anka Salario, said something that stuck with me. She said, "I've been asked many times why the obsession with Mars.

Why go to Mars? Because it's possible. Because space can unite and bring out the best in us.

Because it's one defining step that earthlings will take to light the way into the next centuries. She wasn't being naive about the difficulties. She just spent a year living them.

She was expressing something that I think is true. The pursuit of Mars isn't just about Mars. It's about what it means to be human.

It's about pushing limits. It's about refusing to accept that there are places we cannot go. Every generation needs achievements to celebrate.

Every civilization needs goals that inspire and unite. The moon landings gave us those things. They showed that when we work together, when we commit to a shared goal, we can achieve the impossible.

The 21st century needs something like that. Not because it's practical, not because the return on investment is clear, because societies that stop dreaming start declining, because a species that accepts its limits begins to atrophy because we owe it to ourselves and to future generations to keep pushing. And there's something else.

Mars will make us better. the technologies required to live on Mars, recycling air and water with nearperfect efficiency, generating power in hostile environments, growing food and closed ecosystems, protecting against radiation. These technologies have direct applications to problems on Earth, climate change, resource scarcity, pollution.

The knowledge we gain trying to survive on Mars will help us survive on Earth. This has always been true of space exploration, satellite communications, GPS, weather forecasting, medical imaging, materials science, computer miniaturaturization, all emerged from space research and now benefit billions of lives. The Mars program will generate technologies we can't even imagine yet.

But honestly, that's not why we should go either. Not really. We should go because we're explorers.

Because Mars is there. Because reaching it would be the greatest thing our species has ever done. Because 500 years from now, if human civilization still exists, people will remember two things about the 21st century.

The invention of artificial intelligence and the first human footprints on Mars. Valeri Polyov after returning from his 437 days in space was asked if he would do a Mars mission if offered the chance. He said yes without hesitation.

Despite everything he'd experienced, despite knowing the risks better than almost anyone alive, he would have gone. His wife was sitting next to him when he said it. She responded, "He just says that, but I don't think he was just saying that.

I think he meant it. I think the same drive that made him volunteer for 14 months in a tin can orbiting Earth would have carried him to Mars if given the opportunity. That drive exists in 200,000 people who volunteered for Mars 1.

In the NASA scientists and SpaceX engineers working on the problem right now, in the children looking up at the night sky wondering what it would be like to stand on another world. The physics is hard, the engineering is hard, the money is hard, the politics is hard, but the desire is there. The human raw material exists in abundance.

And throughout history, that's usually been enough. Let me take you somewhere. You're standing in Jezero Crater on Mars.

65 million years ago, when dinosaurs still walked the Earth, this was a lake. Water flowed in from ancient rivers, depositing sediments that might contain evidence of past life. Now it's dry.

Has been for billions of years. Whatever existed here is gone. The ground beneath your feet is rust.

Iron oxide. The same chemistry that makes blood red. Every rock, every pebble, every grain of dust has been sitting here unchanged for eons.

The sky is butterscotch, salmon pink near the horizon, shading to dusty tan overhead. At sunset, the colors reverse from what you know on Earth. The sky near the sun turns blue while the rest remains pink.

It's alien. It's beautiful. It's wrong in a way that reminds you constantly that you're somewhere else entirely.

The silence is profound. No birds, no insects, no wind in trees, cuz there are no trees. Just the whisper of thin atmosphere moving across rocks that have never known life.

You turn slowly, 360°. And everywhere you look, the landscape is empty. No evidence that anything has ever lived here.

Just red rocks and rusty sand stretching to distant mountains under an alien sky. And then you look up. In the night sky of Mars, Earth appears as a bright bluish point of light.

Not a disc, not a marble, a point. Everything you've ever known, everyone you've ever loved, every human who has ever lived or died, every war fought and peace made, every song sung and story told, all of it contained in that tiny speck of light. From where you stand, light itself takes minutes to make the journey between worlds.

If you needed help right now, no one could reach you for months. You are utterly, completely, absolutely alone in a way no human has ever been alone before. This is what we're talking about when we talk about Mars.

Not the engineering, not the budgets, not the risk assessments. This visceral overwhelming experience of being somewhere else entirely, somewhere that doesn't want you, somewhere that will kill you the moment your technology fails. The astronauts who went to the moon reported something called the overview effect.

A cognitive shift that happened when they saw Earth from space. They described sudden overwhelming awareness of the fragility of our planet, the arbitrariness of national borders, the unity of all life. They came back changed.

What would the Mars equivalent be? What happens to the human mind when you're not looking at Earth from a few hundred miles away, but from a 100 million miles? When your home planet isn't a magnificent blue marble, but a barely visible point of light you could cover with your thumb.

I suspect something profound would happen, something we can't predict. The loneliness might be crushing, or there might be a kind of liberation, a clarity that comes from being so far removed from everything familiar that you're forced to confront fundamental questions about existence and meaning. The first humans on Mars will be philosophers, whether they want to be or not.

And then there's the question of what comes next. Mars is not the end. Mars is a beginning.

If we can reach Mars, we can reach the moons of Jupiter and Saturn, the asteroids in centuries, perhaps the nearby stars. I know that sounds like science fiction. I know it's so far beyond current capability that it borders on fantasy, but consider what has already happened.

In 1903, the Wright brothers flew for 12 seconds at Kittyhawk. 66 years later, humans walked on the moon. In less than a single human lifetime, we went from not being able to fly at all to landing on another celestial body.

What might we accomplish in the next 66 years or the next hundred? The universe is 13. 8 billion years old.

Human civilization is about 10,000 years old. Technological civilization is about 300 years old. We are infants in cosmic terms.

We've barely begun to understand what's possible. Mars is the test, the proving ground. If we can build a sustained human presence on Mars, we'll have demonstrated that we're not bound to Earth, that the universe is accessible to us, that our future isn't confined to one fragile planet orbiting one ordinary star.

That matters not just scientifically or economically. It matters philosophically, existentially. What kind of species are we?

What are we capable of? What will we become? For all of human history, we've looked up at Mars and wondered.

The ancient Babylonians tracked its movements. The Greeks named it after their god of war. For thousands of years, it was a wandering light, a celestial mystery.

Then we started to truly see it through telescopes, then spacecraft cameras, then the eyes of rovers crawling across its surface. Mars stopped being a myth and became a place, a real place with geology and weather and a history we're only beginning to understand. But no human has ever seen it directly.

No human has ever stood on that rusty surface and looked up at an alien sky. We've sent our machines, our robot surrogates, but we haven't gone ourselves. There's something incomplete about that.

We've come so close, done so much of the work, solved so many problems, and stopped short of the final step. I believe we'll complete that step. Not because it's easy or cheap or imminent, but because humans don't leave journeys unfinished, because the same drive that carried our ancestors out of Africa and across every ocean will carry us to Mars eventually.

When that happens, when human beings finally stand on the surface of another planet and look back at that pale blue dot in the sky, it will be the greatest achievement in the history of our species, greater than any war or empire built, greater than any invention or discovery. Because we will have proved something that matters. We will have proved that the universe is not too big for us.

That the distances are not too great. that when humanity decides to do something, really decides, nothing can stop us. The physics is hard.

I've spent this entire video telling you how hard. But hard is not impossible. Hard is just another word for something we haven't done yet.

Mars is waiting. It's been waiting for billions of years. patient, indifferent, ready to kill anyone who underestimates the challenge, but also ready to reveal its secrets to anyone bold enough and prepared enough to make the journey.

The question isn't whether we can go. We can. The question is whether we will choose to.

And that choice is ours. Every generation, every decade, every year, we can look up at Mars and remember what humans are capable of. We can decide whether our generation will be the one that takes the next great step.

Whether our era will be remembered as the beginning of humanity's expansion into the cosmos or we can stay home. Accept our limits. Tell ourselves the challenge is too great, the cost too high, the risk too severe.

That's always an option. It's always been an option. Our ancestors could have stayed in Africa.

They could have accepted the horizon as a boundary rather than an invitation. They didn't. And here we are.

Mars is the next horizon, the next invitation, the next test of what we're willing to attempt and what we're capable of achieving. I think we'll pass that test eventually when we're ready. And when we do, when that first human sets foot on Martian soil, they won't just be representing their country or their company or even their species.

They'll be representing every human who ever looked up at the stars and wondered what was out there. They'll be carrying all of us with them. And that means something.

That matters. That's why we're going to Mars.