Nearly every comfortable image people associate with life on Mars is false. The trip is long, domed cities cannot work there, the soil and air are chemically hostile, and even the sky itself is dangerous. Any agricultural base must be manufactured from scratch inside pressurized underground habitats. Mars may be a fascinating place for a research station, but beyond that it is the most aggressively over-marketed pieces of real estate in the Solar System.

The commute is murder

One-way travel time is well over six months. That is a very long time to spend locked in a metal can with no recourse in the event of a serious malfunction, medical emergency, or mental health crisis. Mars is not a vacation. It is an expedition measured in years from the moment you leave Earth.

No homes in domes

The classic image of a bright glass city under a giant dome is not realistic architecture. It is concept art.

On Mars, surface air pressure is under 6 millibars. A shirtsleeve habitat is therefore not "keeping Mars out". It is holding its own atmosphere against near vacuum. A habitat pressurized to roughly Earth-normal conditions pushes outward with about 10 metric tons of force per square meter, or roughly 2,000 pounds per square foot. A dome 100 meters in radius would be trying to lift itself off the ground with hundreds of thousands of tons of total force. The engineering response is not a graceful suburban glass shell. It is a compact pressure vessel, more like a scuba tank than a greenhouse.

Radiation makes the situation even more dire. Surface exposure on Mars is 80 times higher than on Earth. Serious habitats will need substantial shielding, typically by burial or heavy regolith cover. So no, you are probably not getting a sunlit ranch house under a graceful transparent shell. If you have windows at all, the sane version is a small reinforced opening facing a nearby wall of regolith or a canyon face, not a panoramic bubble looking out over the plains.

Great food, no atmosphere

Mars may look like a postcard from New Mexico, but the air is almost pure CO₂, at a pressure equivalent to flying at over 30 km (100,000 feet) above Earth. From a human point of view it is vacuum. To go outside, even for mere seconds, you need a full lunar-style pressure suit [1][2]. Without pressure protection, body fluids begin to boil.

And on Mars that Michelin Man suit is not light. Mars gravity is lower than Earth, but still about 2.4 times lunar gravity, so a suit that is merely miserable on the Moon weighs over 68kg (150 lbs+). Mars is no place for a day hike.

Oops, no food either

The dirt is not soil. It is inert regolith with a heavy dose of perchlorates. Picture watering your plants, with household bleach. This is not a field waiting for seeds. It is a chemically hostile mineral substrate that must be detoxified, conditioned, inoculated, fertilized, watered, and pressure-controlled before it begins to imitate farmland.

There is also no meaningful nitrogen cycle. The Martian atmosphere contains a small percentage of nitrogen, but that figure is misleading because the whole atmosphere is so thin. Earth provides roughly 790 millibars of nitrogen partial pressure overhead. Mars provides only about 0.15. In practical terms, Mars does not have slightly less nitrogen than Earth. It has roughly five thousand times less nitrogen pressure.

Growing food on Mars is not as simple as planting potatoes [3]. Soil and air both need to be heavily preprocessed before anything can grow at scale.

Bloodline exile

Mars missions are governed by launch windows and return geometry, not by human whim. Round-trip crew missions are typically measured in two to three years. Missing the return opportunity can impose a very long additional stay.

Staying too long may also make a return to Earth progressively harder, or even physiologically impossible. Have children there and you are no longer just relocating yourself. You are potentially marooning your own lineage in a gravity well they may never leave.

References:

[1] NASA, (2020). EVA-EXP-0042, Rev. B.
[2] NASA, et al. (2023). "Portable Life Support...", 52nd International Conference on Environmental Systems.
[3] Ridley Scott, (2015). The Martian. 20th Century Fox.