Could Mars be terraformed?

Yes — in theory. But with known physics, Mars terraforming is far beyond our current technology, money, and likely even practical limits.

Main obstacles:

• Atmosphere and warmth: Mars is extremely thin and cold. A 2018 NASA-backed study suggested there isn’t enough accessible carbon dioxide on Mars to build a thick, warm atmosphere by itself.
• Radiation and atmosphere loss: Mars lacks a global magnetic field, so the solar wind keeps stripping away atmosphere.
• Oxygen: Even a thicker atmosphere would still be unbreathable. Making it oxygen-rich would take a very long time, likely thousands of years.
• Soil toxicity: Martian soil contains perchlorates, which are harmful to humans and plants.

What’s more realistic: not full terraforming, but paraterraforming — sealed, pressurized habitats, domes, or underground bases where people can live in Earth-like conditions locally.

Bottom line: Mars could maybe be altered in parts over a very long time, but a truly Earth-like Mars is not something we can expect anytime soon.