When Earth Eventually Grows Old: Why Elon Musk Wants Humanity to Become a Multiplanetary Species
We all know that humanity lives on Earth. But very few of us have seriously thought about one fundamental question:
What will happen when Earth can no longer support human life?
This question may seem impossibly distant because we usually think in terms of decades, centuries, or perhaps thousands of years. But when we look at humanity from the perspective of cosmic time, Earth is not an eternal home.
1. Earth Is Not an Eternal Home
Earth formed approximately 4.54 billion years ago, and the Sun is about 4.6 billion years old.
The Sun is not an eternal energy machine. It produces energy through nuclear fusion in its core, gradually consuming its hydrogen fuel. As time passes, the Sun will undergo dramatic changes.
According to NASA, roughly 5 billion years from now, the Sun is expected to enter the red giant phase of its evolution and expand enormously. Long before or during this stage, the increasing energy output from the aging Sun is expected to make Earth increasingly hostile to life. Eventually, Earth could be engulfed by the expanding Sun or otherwise become completely uninhabitable.
In other words:
Although Earth appears permanent to us, on the cosmic timescale it is only a temporary home for humanity.
Of course, five billion years is almost impossible for us to comprehend.
For an ordinary person today, what happens five billion years from now seems completely irrelevant. Even if we know about it, we might naturally think:
“That is a problem for people billions of generations from now. What does it have to do with me?”
That is a perfectly understandable way of thinking.
But throughout history, there have been individuals who have thought on a timescale far beyond their own lifetimes.
Elon Musk is one of the most prominent examples.
2. Elon Musk Is Thinking About More Than What Happens Five Billion Years From Now
If Elon Musk's long-term vision for space could be summarized in one sentence, it would be:
Make humanity a multiplanetary species.
This does not mean that Musk believes humanity needs to abandon Earth tomorrow. Nor does it mean that Earth is about to become uninhabitable.
His fundamental idea is this:
If human civilization exists on only one planet, then on a sufficiently long timescale, that civilization always has a single point of failure.
Asteroid impacts, supervolcanic eruptions, global wars, catastrophic environmental events, or even risks created by humanity itself could potentially threaten civilization.
But if humanity eventually establishes self-sustaining civilizations on multiple worlds, human civilization would no longer depend entirely on a single planet.
That is the basic idea behind becoming a multiplanetary civilization.
3. He Is Not Just Talking About an Idea—He Is Building the Infrastructure to Make It Possible
What makes Musk's vision particularly notable is that he has not stopped at saying:
“Humanity should go to Mars.”
After founding SpaceX, he began working on some of the most difficult technological obstacles standing in the way of that goal.
One of the most important is:
Reusable Rockets
Traditional rockets have historically been extremely expensive partly because much of the hardware is discarded after each launch.
SpaceX's Falcon program demonstrated the practical use of reusable rocket technology, particularly reusable first-stage boosters.
The next step is even more ambitious:
Starship.
Starship is not simply another rocket.
SpaceX is developing Starship as a fully reusable transportation system intended to carry people and cargo to Earth orbit and, eventually, to the Moon, Mars, and beyond.
SpaceX describes Starship as a key part of its long-term effort to make humanity multiplanetary.
4. Why Does Starship Matter So Much?
If humanity eventually wants hundreds of thousands, millions, or even more people living on another planet, today's space transportation systems would not be sufficient.
Imagine that sending one person to Mars cost hundreds of millions of dollars.
Building a large Martian civilization would be virtually impossible.
So the real question is not:
“Can we send one person to Mars?”
The real question is:
“Can we transport people and cargo to another planet repeatedly, on a massive scale, and at dramatically lower cost?”
That is what Starship is intended to help accomplish.
SpaceX's publicly stated vision for Mars involves concepts such as:
- Manufacturing large numbers of Starships;
- Launching large numbers of spacecraft during appropriate launch windows;
- Transporting large quantities of equipment and supplies to Mars;
- Establishing reliable energy systems;
- Building habitats;
- Using local resources;
- Producing fuel;
- Developing an industrial infrastructure; and
- Eventually creating a self-sustaining and expanding Martian city.
SpaceX has even discussed the possibility that a truly self-sustaining civilization on Mars could ultimately require a population of more than one million people, supported by enormous amounts of cargo delivered to Mars.
This is no longer simply an expedition.
It is the concept of building a new civilization.
5. Why Mars?
If humanity eventually leaves Earth, why Mars?
One reason is that Mars is relatively close to Earth compared with other potentially interesting destinations, while also possessing several characteristics that make it a plausible target for human exploration and settlement.
A Martian day is approximately 24 hours and 40 minutes, remarkably similar to an Earth day. Mars also contains water ice, a carbon-dioxide atmosphere, and other resources. Its surface gravity is about 38 percent that of Earth.
NASA considers human exploration of Mars an important long-term objective and is researching technologies involving life support, oxygen production, energy, transportation, and other requirements for future crewed missions.
Of course, this does not mean Mars is a comfortable place to live.
Quite the opposite:
Mars is an extremely hostile environment.
It is cold and dry, its atmosphere is very thin, and it does not provide air that humans can breathe. Mars also presents challenges involving radiation, dust storms, and low gravity.
Therefore, Musk's vision is not:
“Let's move to Mars the way someone might move from New York to Los Angeles.”
Instead, the concept is:
“Let's gradually transform Mars into another world where human beings can live.”
6. The Real Challenge Is Not Landing on Mars—It Is Surviving There
Sending a few people to Mars is not the same thing as establishing a civilization.
The real challenge is:
How can humans live there for the long term without depending completely on constant resupply from Earth?
They would need to solve problems such as:
Energy
A Martian civilization would require reliable, long-term energy systems.
Water
Humans would need to locate and utilize Martian water resources.
Oxygen
Humans cannot breathe the Martian atmosphere, so oxygen would have to be produced.
NASA's MOXIE experiment demonstrated that oxygen can be produced from carbon dioxide in the Martian atmosphere, an important proof of concept for future human missions.
Food
Martian settlers would eventually need systems for producing food locally.
Buildings
Habitats would have to protect people from radiation, extreme cold, low atmospheric pressure, and other environmental hazards.
Fuel
If all return fuel had to be transported from Earth, the scale and cost of the entire system would become enormous.
That is why using local Martian resources to produce fuel is such an important concept.
One of SpaceX's ideas is to produce methane and oxygen on Mars using locally available resources, potentially allowing a transportation system to become increasingly independent of Earth.
7. The Moon May Be an Important First Step Toward Mars
Musk's ultimate goal is Mars, but humanity is unlikely to jump directly from Earth to a fully developed Martian civilization.
The Moon could become an important intermediate step.
NASA's Artemis program is working toward returning humans to the Moon, and NASA has partnered with SpaceX to develop a Starship-based Human Landing System for transporting astronauts from lunar orbit to the lunar surface.
The future pathway could potentially look something like:
Earth → Low Earth Orbit → Moon → Mars → Other Destinations in the Solar System
And Starship is being developed as an important transportation system within this broader vision.
8. Musk's Real Goal Is Not Simply to Build a “Mars Base”
There is an important distinction here.
A base and a city are completely different things.
An Antarctic research station can be considered a base.
The International Space Station can also be considered a base.
But if a Martian settlement consists of only a few dozen people who depend on Earth for food, equipment, medicine, replacement parts, machinery, and fuel, it is still essentially an outpost of Earth.
A true multiplanetary civilization would require:
Population + Energy + Industry + Agriculture + Construction + Transportation + Technology + Education + Communications + Social Organization
Eventually, these systems would need to form a society capable of growing and expanding.
SpaceX's public vision explicitly refers to the goal of establishing a self-sustaining city on Mars.
That is what makes the idea so extraordinary.
9. Starlink May Also Become Part of a Larger Space Infrastructure
Many people think of Starlink simply as a satellite internet service.
From a business perspective, that is certainly one of its major purposes.
But from a longer-term perspective, a global satellite communications network could also become part of future space infrastructure.
If humanity eventually establishes settlements on the Moon, Mars, or even farther into space, those settlements will need:
Communication, navigation, data transmission, and network infrastructure.
Therefore, many of the technologies being developed by SpaceX are not necessarily isolated projects.
Rockets solve the problem of transportation.
Starlink addresses communications.
Starship aims to address large-scale transportation.
And the ultimate objective is:
To establish a permanent human presence beyond Earth.
10. AI, Robotics, and Advanced Manufacturing Could Also Play a Role
Building a city on Mars would make it impractical to rely on large numbers of humans to perform every dangerous, repetitive, and physically demanding task.
That is one reason why artificial intelligence, robotics, and automated manufacturing may become increasingly important.
Tesla is developing technologies involving AI, robotics, electric vehicles, and large-scale manufacturing. Tesla's long-term plans connect these technologies with the broader goal of increasing productivity through automation and advanced manufacturing.
Imagine applying these technologies to Mars.
Robots could arrive before humans.
They could:
- Build infrastructure;
- Move equipment;
- Extract resources;
- Construct buildings;
- Install solar or other energy systems;
- Prepare habitats;
- Perform dangerous work in hostile environments.
In other words:
The first builders of a Martian civilization may not all be human.
11. But This Does Not Mean We Should Abandon Earth
There is one point that must be emphasized.
Making humanity multiplanetary does not mean abandoning Earth.
Earth remains the only known planet that naturally supports large-scale human civilization.
Compared with Earth, Mars is an extraordinarily hostile environment.
Therefore, protecting Earth remains one of humanity's most immediate and important responsibilities.
The better approach is:
Protect our first home while working to establish a second home.
Just as a family would not intentionally destroy its first house simply because it eventually acquired a second one.
12. What Is Most Remarkable Is the Timescale
Our generation may never see a truly independent Martian city.
Even our children, grandchildren, or great-grandchildren may not see one.
But many of humanity's greatest achievements were never completed within the lifetime of a single individual.
The pyramids were like this.
Cathedrals were like this.
Railroads were like this.
Modern cities were like this.
The Internet was like this.
If humanity eventually establishes a civilization on another planet, it could become one of the largest long-term projects in human history.
It could take decades, centuries, or perhaps much longer.
But someone has to take the first step.
13. Why Should We Care About What Happens Five Billion Years From Now?
Someone might ask:
“What does it matter to me what happens to Earth five billion years from now?”
The answer does not necessarily have to be based on personal benefit.
The meaning of civilization has never been limited to the lifespan of one individual.
The cities, roads, universities, hospitals, scientific knowledge, technologies, and cultural achievements we use today were largely inherited from previous generations.
The people who created them knew that they might never see their ultimate results.
Yet they built them anyway.
Great civilizations have always possessed the ability to:
Invest in a future they themselves may never see.
If humanity eventually establishes itself on other planets, the pioneers who begin that process may be remembered hundreds, thousands, or even millions of years from now.
14. Musk's Real Goal May Be Even Bigger Than “Colonizing Mars”
When Musk's publicly stated ambitions are viewed together, an interesting progression emerges:
Reusable rockets
↓
Large-scale access to space
↓
Lunar and deep-space exploration
↓
Transportation to Mars
↓
A Martian base
↓
A self-sustaining Martian city
↓
A multiplanetary civilization
↓
Eventually expanding human civilization throughout the Solar System and perhaps beyond
SpaceX's public vision describes an eventual expansion from a Martian civilization toward the broader Solar System and, potentially, even farther.
This is no longer simply a traditional aerospace project.
It is an attempt to address one of the ultimate questions facing human civilization:
Can humanity transform itself from a civilization living on a single planet into a civilization capable of existing across multiple worlds?
Conclusion: We Are Visitors on Earth—and Builders of the Future
From the perspective of an individual human life, five billion years is unimaginably far away.
But from the perspective of the universe, five billion years is not eternity.
The Sun will eventually age.
Earth will eventually undergo profound changes.
And if human civilization wants a truly long-term future, it may eventually need to reduce its dependence on a single planet.
The most important thing about what Elon Musk is doing may not be whether he can build a Martian city according to today's projected schedule.
Those specific timelines will inevitably change as technology develops.
What matters more is the direction he is trying to establish:
Transform humanity from a civilization with only one home into a civilization with multiple homes.
Perhaps our generation will see only the beginning.
Perhaps the first permanent settlers on Mars are still many years away.
Perhaps a genuine Martian city will not exist until the time of our descendants—or generations far beyond them.
But if one day human beings really do stand on Mars and look back at that small blue planet in the sky, they may realize something extraordinary:
There was once a time when every human being lived on the same planet.
And perhaps the era we are living through today will eventually be remembered as the beginning of the end of that period.
From “humanity on one planet” to “humanity across multiple planets.”
That may be the truly extraordinary meaning behind the vision of “Making Life Multiplanetary.”
Gang Chen, Publisher/Bestselling Author (GreenExamEducation.com)
