Today’s businesspeople are very excited about launching into the stratosphere. Whether it’s Elon Musk’s SpaceX, Richard Branson’s Virgin Galactic, the Mars One mission, or a slew of other aerospace enterprises, a host of companies are trying to help humans leave the rocky planet we’ve called home for the past six million years. But some critics argue that instead of finding a nook elsewhere in the solar system, we really ought to be focusing on solving the issues with our own planet.

Ron Garan, a former NASA astronaut, believes we should not be abandoning hope for continued life on planet Earth in favor of rubbing shoulders with Martians. He has spent time on the International Space Station (ISS), done four spacewalks, and has been awarded both the NASA Exceptional Service medal and the NASA Space Flight medial. Back on land, Garan spends his time focusing on bettering the home we already have. “Being so far away from Earth makes you see how similar and interconnected everything is,” he says, “rather than us compartmentalizing home.”

To be clear, Garan isn’t opposed to exploring the notion of colonizing Mars: It’s just that we should be using the innovative technologies we’re developing to live up there to make life better down here. Human curiosity is one of the biggest drivers for space exploration, and it “keeps us hungry to continuing wanting to innovate and solve these problems,” he says.

It may be a moonshoot, but perhaps if we aim for the moon, we’ll land on the stars.

This conversation has been lightly condensed and edited for clarity.

Considering you are one of the few people who have left Earth, how have you come to form the opinion that we shouldn’t colonize Mars?

I think we should explore other planets, but I don’t think we should abandon this planet to go live on Mars. It just doesn’t make any logical sense that we would leave this planet for an inhospitable one like Mars. First of all, if we can’t even “terraform”—which is to control our climate and environment—our own planet, what makes us think that we can go to another planet and control the environment there? If we developed the capability to terraform and create atmospheres and climates on other planets, then we should apply that capability to benefit our home planet.

From Elon Musk to Richard Branson, private entrepreneurs are sending a lot of money up into space. Would it be best to redirect that capital toward solving the problems that already exist on Earth?

I think funding should go to both. Space is our future; we need to devote resources and time and effort toward further exploration of our solar system, including human exploration. The primary reason for doing this is not so that we can have a plan B, via having another planet we can go live on, but instead so that we can use the technology that’s developed through those efforts to help us here on Earth.

Carl Sagan basically said that for the foreseeable future, Earth is where we make our stand. So if there is nowhere else we can go right now, we need to take this really seriously.

NASA STS-124 Mission Specialist Ronald J. Garan.

Have you always felt this way, or was there a moment when you realized the importance of focusing on the Earth instead of the stars?

I’ve always had the idea that everyone has a responsibility to leave this place a little bit better than how they found it. But going to space broadened, reinforced, and amplified that opinion.

The Earth is just incredibly beautiful when viewed from space, and all those buzzwords you’ve heard astronaut after astronaut say about how beautiful and tranquil and peaceful and fragile this planet looks from space—those are all true. It really does look like this jewel in the blackness of space; a fragile oasis. I try to use this perspective of our planet to inspire people to make a difference, mind the ship, and take care of our fellow crewmates on Spaceship Earth.

Why are so many people obsessed with getting off planet Earth?

I wanted to be an astronaut ever since July 20, 1969. That was the day when I, along with millions and millions of people all around the world, watched those first footsteps on the moon on TV. I wouldn’t have been able to put it in these words at the time, but even as a young boy, on some level I realized that we had just become a different species. We had become a species that was no longer confined to this planet, and that was really exciting to me.

I wanted to become a part of that group of explorers that got to step off the planet and look back upon ourselves. I think continuing that exploration out into the solar system and beyond is part of human nature. We are explorers by nature. We want to expand our knowledge and expand our understanding of our universe.

Is it common among astronauts that once you finally leave Earth and can look back upon it from space, you have an urge to go straight back to protect it?

I don’t want to speak for other astronauts, cosmonauts, or taikonauts, but most of the people I know who’ve had this experience have come back with a deeper appreciation for the planet that we live on. And it’s not just an appreciation for the planet—it’s appreciation for the living things on the planet, too.

One of the things I experienced in space is what I can only describe as a sobering contradiction: a contradiction between the beauty of our planet and the unfortunate realities of life for a significant number of its inhabitants. It’s obvious from space that life on our planet is not always as beautiful as it looks from space.

The other thing I’ve experienced was a profound sense of gratitude: gratitude for the opportunity to see the planet from that perspective, and gratitude for the planet that we’ve been given. Being physically detached from the Earth made me feel deeply interconnected with everyone on it in some way that I really can’t fully explain. It’s very obvious from that vantage point that we are all not only deeply connected, but also deeply interdependent as well.

What new discoveries have we uncovered in our exploration of the universe that have been particularly revolutionary back on Earth?

There’s the technology side, and there’s then there’s perspective. Perspective is very powerful. That first time that we looked back and saw this planet from space—Earthrise—was incredibly revolutionary. That photograph of Earthrise is certainly the most influential environmental photograph ever taken. It was credited for inspiring the first Earth Day in 1970, and it’s helped launch the modern environmental movement. It really shows the truth, the reality of the world we live in; that we’re on this oasis, and it’s all we have.

So there’s that aspect of it, but there’s also all the technology that comes from the space program, whether it’s computing technology, energy production through things like solar energy, or all of the implications for medicine and medical diagnostics. We do a tremendous amount of Earth observation from space that gives us a profound increase in understanding of our planet and its life-support systems that we would not have insight into if we didn’t have a space program.

NASA Earthrise, 1968.

Why do you think there are so many conversations about Martian colonization? Have we lost hope for Earth?

This idea that we are going to abandon Earth and go live on Mars is utter nonsense. It’s illogical. It makes perfect sense to expand human presence to Mars, but we’re not going to abandon Earth. If we had the capability to colonize and terraform Mars to make it habitable for humans, then we certainly could control what’s happening on our own planet, which has a head start of millions of years.

What conversation should we be having instead?

The first place we should establish a permanent human presence in our solar system is the moon, our closest neighbor. And then from there, establish transportation infrastructure to allow regular flights between the Earth and the moon. Then from there, we could use it as a jump-off point and have that be a transportation hub to the rest of the solar system. That makes perfect sense to me.

We need to basically take parallel paths: We need to be exploring the solar system because of all the benefits to humanity that that will incur, while also devoting as much effort to being able to control the life-support systems of Spaceship Earth.

If we expand milestones such as the accomplishment of the Sustainable Development Goals (SDGs) by 2030 and having complete decarbonization by 2050 out to 2068—which is the 100-year anniversary of Earthrise—I believe we should have complete control of the life-support systems on our planet by then. If we had complete control of the chemical constituents of our atmosphere, soil, land, and oceans, we’d be able to monitor it and adjust it—and optimize it for life.

Why are we having more conversations about living on Mars than the potential of being able to control our own atmosphere on Earth? Learning how to counteract climate change and other environmental factors here instead of establishing colonies elsewhere seems far more beneficial.

Well, it’s a moon shot, right? It’s something that’s going to take a lot of effort and a lot of time to accomplish, but we started this conversation off with terraforming Mars. It’s a lot easier to control our own atmosphere and our own oceans than it is to create an entirely new atmosphere.

What are you currently trying to achieve back on Earth?

I’ve got a non-profit that I founded and am still involved in, and I have a lot of social enterprises that I’m involved in. Most of the stuff I work with in that sector is around being able to provide clean water to folks, because I think it’s really important to do that in an environmentally, financially sustainable way.

I’m also involved with an effort called Constellation, which is bringing together a coalition of international astronauts, visionaries, and futurists to put out a call to the world to crowdsource and co-imagine a vision of our future. We’re not going to be able to get to the vision of our future we want if we don’t learn how to work together on a planetary level, not just a local level.

My primary day job is working as the chief pilot for a company called World View, which is trying to launch all kinds of things—including people—to the edge of space in high-altitude balloons. This project has tremendous environmental capabilities as far as being able to hover these platforms over a specific area of interest to do things like monitor the oceans, coral reefs, or how much CO2 is in the atmosphere. From it, we might be able to develop better ways to do climate modeling, weather predictions, and agricultural optimization.

For those who would still want to go live on Mars, what kinds of over-romantic notions do people have about living in space?

You can’t be claustrophobic, because if you’re going to Mars, you’re gonna be in a can for six to eight months. And once you get there, you’re still gonna be living in a tin can. There are a lot of things that define the beauty of life on our planet, like the breeze in your face, mist on a lake, and the sound of the birds. If you’re going to live on Mars, you’re not gonna have that for the rest of your life. That’s not so romantic to me.

What is romantic is expanding the body of human knowledge and expanding human presence. It’s not going to be all fun. Those pioneers who will eventually be exploring Mars are going have to deal with hardships. I’m sure there will be a lot of people who get homesick, which is an interesting thought: When you get that far away from the planet, your definition of home changes radically. Home simply becomes Earth.