Mars will not be habitable in any Earth-like sense within our lifetimes, our children’s lifetimes, or likely even within the next several thousand years. The planet lacks a thick atmosphere, a global magnetic field, and warm enough temperatures for liquid water on its surface. Making Mars truly habitable, where you could walk outside without a spacesuit, would require planetary-scale engineering that remains far beyond current or near-future technology. What is on the horizon, potentially within the next few decades, is humans living on Mars inside artificial habitats: pressurized shelters with manufactured air, radiation shielding, and imported or locally produced supplies.
Humans on Mars vs. a Habitable Mars
These are two very different things, and the distinction matters. Sending people to live on Mars in enclosed habitats is a goal that space agencies and private companies are actively working toward. NASA has outlined plans to send humans to Mars in the 2030s, a timeline established in the NASA Authorization Act of 2010. SpaceX has been more aggressive, with Elon Musk describing a step-by-step plan that targets uncrewed Starship landings as early as 2026 or 2027, followed by the first crewed mission around 2028 to 2029. Musk has repeatedly shifted these dates (earlier targets included 2018 and 2022 for uncrewed landings, neither of which happened), so healthy skepticism is warranted.
Even in the most optimistic scenarios, those early settlers would live in something closer to a submarine or space station than a village. Every breath of air, every drop of water, and every calorie of food would need to be produced or recycled inside sealed structures. That’s survivable, not habitable in the way we normally use the word.
Why Mars Is So Hostile Right Now
Mars has a thin atmosphere made almost entirely of carbon dioxide, with surface pressure less than 1% of Earth’s. That’s too thin to breathe, too thin to keep liquid water from boiling away, and too thin to block dangerous radiation. Average surface temperatures hover around minus 60°C (minus 80°F). The planet also lost its global magnetic field billions of years ago, which means the solar wind continuously strips away atmospheric gases and cosmic radiation reaches the ground largely unimpeded.
Radiation is one of the most serious health concerns. The average radiation background on Earth is about 2.4 millisieverts per year. On the International Space Station, astronauts absorb roughly 0.5 millisieverts per day, more than 75 times the annual Earth rate. Mars offers slightly more protection than open space because the planet itself blocks radiation from below and the thin atmosphere filters a small amount, but exposure levels still far exceed what space agencies consider safe for career limits. A 650-day Mars mission at solar minimum would push astronauts past NASA’s current career limit of 600 millisieverts, even with aluminum shielding.
The soil presents its own problems. Martian regolith is laced with perchlorates, toxic salts that corrode equipment and are hazardous to human health at low concentrations. Any water extracted from subsurface ice would be contaminated with these compounds and would need treatment before it could be used for drinking, farming, or fuel production.
What Terraforming Would Actually Require
Terraforming means transforming Mars into a planet where humans can live on the surface without enclosed habitats. This would require thickening the atmosphere to a pressure that supports liquid water and breathable air, warming the planet by tens of degrees, and shielding it from solar wind so the new atmosphere doesn’t get stripped away again. Each of these steps involves challenges that range from extraordinarily difficult to currently impossible.
A 2018 NASA-supported study concluded that terraforming Mars is not possible using present-day technology. The planet simply doesn’t have enough accessible carbon dioxide to thicken its atmosphere to Earth-like levels through any known method. Even if atmospheric loss were somehow halted, natural volcanic outgassing on Mars is so minimal that it would take roughly 10 million years just to double the planet’s current thin atmosphere.
Artificial approaches have been proposed. Some researchers have modeled injecting super-greenhouse gases or hydrogen into the Martian atmosphere. Simulations of ancient Mars suggest that 1.5 to 2 bars of carbon dioxide with at least 3% hydrogen could push global average surface temperatures above freezing. But producing and delivering those gases at planetary scale, and keeping them there, remains purely theoretical.
The Magnetic Field Problem
Before any thicker atmosphere could survive on Mars, you would need to solve the magnetic field problem. Without a magnetosphere, solar wind would gradually erode any atmosphere you managed to build. One widely discussed idea is placing a magnetic shield at the point between Mars and the Sun where their gravitational pulls balance out (called the L1 Lagrange point). It sounds elegant, but a detailed study published in the International Journal of Astrobiology found that the most intuitive version of this plan, a compact electromagnet at that location, is simply unfeasible.
The more practical design, according to that study, would involve wrapping a superconducting wire around Mars at its equator, creating a loop roughly 3,400 kilometers in radius. This version would have a mass of about 1 billion kilograms, far less than the compact design (which would require mining roughly 10% of Mars itself for superconducting material). The equatorial loop would “only” require mining about 0.1% of Olympus Mons. That’s more feasible in principle, but building a planet-encircling superconducting wire is an engineering challenge that dwarfs anything humanity has ever attempted.
Small Steps Already Underway
Some foundational technologies are being tested right now, though they’re designed for small outpost survival rather than terraforming. NASA’s MOXIE experiment aboard the Perseverance rover demonstrated that oxygen can be produced directly from Mars’s carbon dioxide atmosphere. By late 2022, MOXIE was generating nearly 10.56 grams of oxygen per hour at peak and sustaining about 9.8 grams per hour over 40-minute runs. That’s a tiny amount, roughly enough to keep a small dog alive, but it proved the chemistry works on Mars.
Water purification is another active area. NASA-funded researchers are engineering bacteria that can break down perchlorates in Martian water, converting these toxic salts into harmless chloride and usable oxygen. The system would launch as dried bacterial spores, stable at room temperature for years, and be activated in a bioreactor after arrival. Unlike traditional water filters that just collect contaminants, this approach eliminates perchlorates entirely, making it more sustainable for long-term use.
SpaceX’s broader plan envisions scaling up dramatically over time: 5 Starship launches in 2026, 20 in 2028, 100 in 2031, and eventually 1,000 to 2,000 ships per launch window, each carrying 100 to 200 passengers. Whether or not those numbers hold, the underlying vision is a self-sustaining colony that grows over decades.
Realistic Timelines
If you’re asking when you could visit Mars and walk around in a pressurized habitat, the answer is possibly within the next 20 to 30 years, assuming crewed missions proceed roughly on schedule. Early outposts would be small, dangerous, and deeply dependent on supply shipments from Earth.
If you’re asking when you could walk on the Martian surface in a t-shirt and breathe the open air, the honest answer is: not for centuries at the absolute minimum, and more likely thousands of years, if ever. The engineering required to build a magnetic shield, thicken the atmosphere, warm the planet, and make the soil safe operates on timescales and at resource demands that make it impossible to assign a meaningful date. Current scientific consensus puts full terraforming firmly in the category of theoretically possible but practically out of reach for the foreseeable future.
The gap between “people living on Mars” and “Mars being habitable” is roughly the same as the gap between living in a submarine on the ocean floor and turning the ocean floor into dry land. The first is hard but achievable. The second requires reshaping a world.