It's impossible to know from a practical standpoint, but many scientists believe it's theoretically possible for humans to cultivate an Earth-like environment on Mars. This process is known as "terraforming," a Latin-derived word that means "Earth shaping." Terraforming Mars would be an extremely difficult, if not impossible task due to differences between Mars's and Earth's gravities, atmospheres and climate conditions.
In addition to the logistical, technical and physical challenges associated with terraforming Mars, there are ethical arguments against Martian terraforming. Some experts argue that a human takeover of Mars could be harmful to potential native life forms, known or undiscovered.
If terraforming Mars is possible, humans would have to impose sweeping change to a massive planetary system. Basic factors such as the planet's temperature and atmospheric density would need to be changed. Some scientists believe that we are capable of this. Whether they're correct or not remains to be seen.